LEAVES AND STIPULES

Perrier de la Bâthie (1943, 1950) placed considerable emphasis on leaf morphology. We have investigated this in greater detail and conclude that variation in leaf shape, texture, color (in dried specimens), margin type, the abaxial surface indument, and type of venation are particularly important. Most species of Gouania have ovate leaves, but exceptions include: G. callmanderi Buerki (elliptic to ovate-elliptic), G. humbertii H. Perrier (orbicular), G. mauritiana (lanceolate to deltoid), and G. laxiflora Tul. (cordate). The majority of the species have subcoriaceous leaf blades, but G. cupreifolia Buerki, Phillipson & Callm. has distinctly thicker, more rigid coriaceous blades, while G. zebrifolia Buerki, Phillipson & Callm. has thinner, more flexible membranous blades. Leaves of most species are more or less concolorous when dried but are notably discolorous in others (e.g., G. phillipsonii Buerki). Leaf margins are generally entire, but some taxa have denticulate (G. ambrensis Buerki, Phillipson & Callm.) or serrate (G. mauritiana) margins. The abaxial surface of immature leaves usually possesses some kind of indument, but this is often caducous, giving rise to glabrous mature leaves. In other species the indument is persistent and sometimes very dense, variously distributed and composed of trichomes that differ in color, length, and orientation. The presence of strong tertiary veins arising from the secondary veins is also a valuable taxonomic character. Most of the species have at least one well-developed tertiary vein arising from the lowest pair of secondary veins (in addition to the fine reticulate network of tertiary veins that is present throughout the leaf), whereas only two species (G. humbertii and G. lineata Tul.) completely and consistently lack conspicuous tertiary veins. Among all the taxa present in the region, G. taolagnarensis Buerki, Phillipson & Callm. has particularly well-developed venation, with even some conspicuous quaternary veins present arising from the first pair of tertiary veins. In this species the venation is more developed on one side of the leaf, causing the leaf base to be asymmetric. The reticulation is noticeably scalariform in most species; however, this pattern is inconspicuous in some taxa (e.g., G. pannigera Tul.). A dark brown triangular marking at the base of the stipule has been noted only in G. ambrensis.

FLOWERS AND INFLORESCENCE

Perrier de la Bâthie (1943) made extensive use of the shape of the hypanthium and the form of the nectary disc in delimiting taxon. Our studies confirm the importance of these characters and have revealed other variations in these organs of which Perrier de la Bâthie was apparently unaware, that we believe are also taxonomically useful. Most species have an obconic hypanthium, but Gouania cupuliflora Buerki, Phillipson & Callm., G. gautieri Buerki, Phillipson & Callm., and G. humbertii have a cupulate hypanthium. The nectar disc is always lobed, but the relative length of the lobes is highly variable. At one extreme, short lobes occur in G. aphrodes Tul. that reach only about one sixth of the length of the sepals, and at the other extreme the lobes of G. laxiflora are as long as or longer than the sepals. Moreover, the lobes of the disc within a single flower are markedly unequal in length in G. scandens (Gaertn.) R. B. Drumm. subsp. glandulosa (Boivin ex Tul.) Buerki, Phillipson & Callm. All species appear to have 3-lobed stigmas except those of G. cupuliflora, which are 2-lobed. The flowers may be sessile or pedicellate and grouped in either sessile or pedunculate glomerules, and the indument of the peduncles and pedicels is variable.

Distribution and ecology

Gouania ambrensis is endemic to Montagne d’Ambre in the north of Madagascar (Fig. 2B). This species grows on basement rocks in the transitional zone between humid and dry forest at an elevational range of 400 to just over 1000 m.

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Figure 2

Distribution of Gouania species occurring in Madagascar, mapped on the bioclimatic zones (after Cornet, 1974; adapted by Schatz, 2000). —A. G. callmanderi (triangle), G. perrieri (star), G. phillipsonii (square), and G. zebrifolia (circle). —B. G. ambrensis (star), G. cupreifolia (triangle), G. lineata (square), and G. pannigera (circle). —C. G. cupuliflora (square), G. gautieri (star), G. taolagnarensis (triangle), and G. scandens subsp. glandulosa (circle). —D. G. aphrodes (square), G. humbertii (star), G. laxiflora (triangle), and G. myriocarpa (circle).

IUCN Red List category

Gouania ambrensis has an EOO of 14 km² and an AOO of 27 km², and consists of two known subpopulations, one of which occurs in a protected area. It is therefore assigned a preliminary status (IUCN, 2001) of Endangered (EN B2ab[ii]).

Phenology

This species has been collected in flower in October, with immature fruit in October and mature fruit in November.

Etymology

The epithet of the new species refers to its endemic locale, on Montagne d’Ambre in Antsiranana Province.

Discussion

Perrier de la Bâthie recognized this taxon as Gouania mauritiana var. latiloba, affiliated with G. mauritiana subsp. aphrodes (Tul.) H. Perrier, both infraspecies mentioned by him in 1943. The varietal name was not accompanied by a Latin description or diagnosis and is therefore not validly published, according to the International Code of Botanical Nomenclature (ICBN; McNeill et al., 2006: Art. 36.1). In this study we consider it to be a distinct species distinguished from others in the region by the combination of the following characters: ovate leaves; the presence of the dark brown, triangular mark on the basal part of the stipule inner surface (absent in all other species); the whitish indument on its inflorescence axes; the densely silvery-pubescent flowers; the lobes of its floral disc, which are one half as long as the sepals; and its mature fruits that are covered with a silver to whitish indument.

Paratypes

MADAGASCAR. Antsiranana: Montagne d’Ambre, versants est, 12°34′S, 49°13′E, S. M. Trigui, M. H. Razanajatovo & S. D. Ramandimbimanana 332 (G, K, MO, P, TEF); Près d’Ambavahibe, H. Perrier de la Bâthie 17700 (K, P); Montagne d’Ambre PA, rd. to Joffreville, 12°31′S, 49°10′E, F. I. van Nek 1819 (TAN, WAG); Montagne d’Ambre PA, NNW of Les Roussettes, 12°28′S, 49°10′E, F. I. van Nek 1901 (TAN, WAG); Montagne d’Ambre PA, F. I. van Nek 1904 (TAN); Montagne d’Ambre PA, along rd. N of Joffreville, 12°29′S, 49°12′E, F. I. van Nek 1939 (TAN, WAG).

2. Gouania aphrodes Tul., Ann. Sci. Nat., Bot. sér. 4, 8: 132. 1857, as “Guania.” Gouania mauritiana Lam. subsp. aphrodes (Tul.) H. Perrier, Notul. Syst. (Paris) 11: 34. 1943. TYPE: Madagascar. Antsiranana: Hellville, Nov. 1847 (fr.), L.-H. Boivin 2171 (lectotype, designated here, P!; isotype, G[2]!). Figure 3A.

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Figure 3

—A. Gouania aphrodes, leaf with detail of the margin. B–D. Gouania zebrifolia. —B. Habit. —C. Flower, showing the lobes of the disc reaching halfway along the sepals. —D. Leaf, showing its denticulate margin. A drawn from Gentry 11892 (TAN); B–D from Gautier et al. 4263 (TEF).

Gouania eriocarpa Tul., Ann. Sci. Nat., Bot. sér. 4, 8: 133. 1857, as “Guania.” TYPE: Comoro Islands. Grande Comore: au-dessus de Vouni, Mai 1850 (fr.), L.-H. Boivin s.n. (holotype, P!; isotype, G!).

Gouania pannigera Tul. f. macrophylla Tul., Ann. Sci. Nat., Bot. sér. 4, 8: 134. 1857, as “Guania” and “macrophyllam.” TYPE: Comoro Islands. Grande Comore: au-dessus de Vouni, Mai 1850 (fr.), L.-H. Boivin s.n. (holotype, P!).

Woody liana; stems dark green, drying brown to ferruginous, finely pubescent to villous with somewhat caducous beige trichomes; stipules finely pubescent with beige trichomes, 2(–3) × ca. 0.75 mm; tendrils pubescent. Leaves ovate; petioles (5–)10–15(–25) mm, pubescent with beige trichomes; leaf blades (4–)5.5(–8.5) × (2–)3.5(–5) cm, discolorous; secondary veins alternate, 6 to 7(to 10) pairs, not reaching the margin but following it; tertiary veins apparent, arising generally only from the second or third secondary veins, reticulation scalariform; abaxial surface densely pubescent to villous with beige trichomes, somewhat glabrescent (Malagasy specimens have a denser indument than those from the Comoro Islands); midrib, secondary veins, and tertiary veins slightly prominent; adaxial surface glabrescent; margin denticulate near the apex, every sinus with an apical tuft of beige trichomes; base rounded and sometimes shallowly cordate; apex acuminate. Inflorescences congested, covered with an indument similar to stems, (7–)13(–17) cm; glomerules sessile, (4 to)5- to 6-flowered; bracts densely pubescent on both surfaces with a beige indument, caducous, (2–)3 × ca. 1 mm; flowers and fruits pedicellate, pedicels to 1 mm, densely pubescent with white trichomes. Hypanthium broadly obconic, becoming subglobose as the capsule develops; sepals triangular, ca. 1.3 × 1 mm, brown to reddish when dried, outer surface densely pubescent, inner glabrous; petals ca. 1 × 0.5 mm, white; stamens slightly longer than petals, with a pale brown filament and a pale brown globose anther ca. 0.1 × 0.1 mm; disc flat, shallowly 5-lobed, ca. 3 mm diam.; lobes ca. 0.2 mm, thickened, truncate, 1/6 as long as the sepals; stigma with 3 linear lobes, those ca. 0.8 mm, style ca. 1 mm. Fruits 0 or 1 developing on each glomerule, spheroid (ca. 0.8 × 0.8 cm), glabrescent to glabrous, equally distributed throughout the infructescence; valves ca. 9 × 5 mm; seeds brown, shiny, ovoid, and slightly flattened, ca. 3 × 2 × 1 mm.

Distribution and ecology

Gouania aphrodes occurs in northern Madagascar and the Comoro Islands (Anjouan, Mayotte, and Mohéli) (Fig. 2D). It grows on margins of evergreen lowland forest at an elevational range from sea level to 500 m.

IUCN Red List category

Within Madagascar, Gouania aphrodes has an EOO of 30,560 km², an 2 AOO of 81 km², and six known subpopulations, one of which occurs in a protected area (Manongarivo). Based on IUCN Red List criteria (IUCN, 2001), we assign a preliminary status of Vulnerable (VUB2ab[ii]) for this species in Madagascar. Its conservation status in the Comoro Islands has not been assessed.

Phenology

This species has been collected in flower in May and in fruit in August.

Discussion

Gouania aphrodes was based on four syntypes: Boivin 2171, Boivin 2646, Pervillé 339, and Richard 133 (Tulasne, 1857). A syntype at P bears a single label with the two collection numbers Boivin 2646 and Richard 133 written on it; the origin of this collection is unclear and therefore would not be a suitable choice as lectotype. We select Boivin 2171 as lectotype over Pervillé 339, because it is in better condition, and two duplicates are present at G.

Perrier de la Bâthie (1943) regarded this taxon as a subspecies of Gouania mauritiana. He also recognized two other subspecies of G. mauritiana from Madagascar: G. mauritiana subsp. pannigera (Tul.) H. Perrier and G. mauritiana subsp. myriocarpa (Tul.) H. Perrier. We treat these three infraspecific taxa as separate species, distinct from G. mauritiana. Furthermore, Perrier de la Bâthie (1943) recognized three varieties within his G. mauritiana subsp. aphrodes: the typical variety, as well as two others (G. mauritiana var. angustiloba H. Perrier, G. mauritiana var. latiloba). Neither varietal name was validly published by Perrier de la Bâthie, and in our opinion these taxa also merit recognition at the species level. They are described herein as G. ambrensis and G. cupuliflora.

Gouania aphrodes can be easily distinguished from G. pannigera (to which it is most similar) by its leaves, which are acuminate (vs. rounded to subacute in G. pannigera), having a fine, light brown indument on the abaxial surface (vs. a reddish brown indument) and denticulate margins (vs. entire or sometimes with one or two teeth near the teeth), and also by its small (ca. 0.8 × 0.8 cm), glabrescent or glabrous fruits (vs. larger, ca. 1 × 1.4 cm, sparsely reddish pubescent fruits). Furthermore, G. aphrodes grows in evergreen lowland forests at elevations of 0–500 m in northern Madagascar and the Comoro Islands, while G. pannigera colonizes the evergreen montane forests and disturbed areas at 800–1500 m in the central highlands of Madagascar.

Additional specimens examined

COMORO ISLANDS. s. loc., fr., Boivin s.n. (G, P); fl., Humblot 25 (K). Anjouan: Anjouan, s.d., Boivin s.n. (P); Johanna Island, Meller s.n. (K). Mayotte: Grande Terre, Ouangani, Hachike, Barthelat & M’Changama 428 (G, K, MO, P); Grande Terre, Ouangani, Coconi, carrefour d’Hachike, Barthelat et al. 882 (G, K, P); s. loc., fl., Boivin 3366 (G, K); Forêt de Mazé Mont Bini, Humblot 1025, 1029 (P); Coconi, secondary thicket behind Director of Agriculture’s residence, Lorence 2891 (P); Sohoa, Pascal 557 (G, K, MO, NY, P, TEF, WAG); Coconi, Tingy 796 (P). Mohely [Mohéli]: inful. Mohely, s.d., Boivin s.n. (P); Nioumachoua, Mtrawia, Labat et al. 3740 (G, K, MO, P). MADAGASCAR. s. loc., “Central Madagascar,” fr., Baron 302 (K); fr., Baron 6521 (K). Antsiranana: Ambilobe, Decary 14789 (P); W base of Manongarivo Massif, Gentry 11892 (K, MO, P, TAN); A’Mananjeba (Nord), Sambirano, Perrier de la Bâthie 6019 (P); Massif du Manongarivo, Perrier de la Bâthie 6040 (P); Nosy Be, Pervillé 339 (K, P); Ambonitohaka, Réserves Naturelles 12657-RN (TAN); Vohémar, Richard 133 (P). Mahajanga: Vallée de l’Antsahakolany, Decary 2160 (G, P); Bejofo, Decary 2202, 2208 (P); Mandritsara, Hb. Jard. Bot. Tananarive 16 (P); bassin moyen du Bemarivo (Boina), Perrier de la Bâthie 6038 (P).

3. Gouania callmanderi Buerki, sp. nov. TYPE: Madagascar. Toliara: 17 km de Sakaraha, bord de la RN7, 22°53′23″S, 44°40′43″E, 763 m, 19 Mar. 2005 (fl., imm. fr.), S. Buerki, P. B. Phillipson & C. Rakotovao 61 (holotype, MO!; isotypes, BR!, G!, K!, P!, S!, TAN!, US!, WAG!). Figure 4.

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Figure 4

Gouania callmanderi. —A. Flower, showing the lobes of the disc reaching one fourth of the way along the sepals. —B. Immature fruit covered by a yellow indument. —C. Habit, showing the long pedicels. —D. Leaf, showing the lack of visible tertiary veins. —E. Fruit. A, D drawn from the holotype Buerki et al. 61 (MO); B, C from Buerki et al. 55 (TAN); E from Bosser 28 (TAN).

Haec species a congeneris madagascariensibus foliis parvis ellipticis usque ovato-ellipticis abaxialiter indumento albido obtectis, floribus pedicellis longis insidentibus, disci lobis longitudine 1/4 sepalorum partem attingentibus atque fructu juvenili indumento luteo obtecto facile distinguitur.

Woody liana climbing to 8 m; stems dark green, drying brown, finely pubescent to villous with brown to whitish trichomes; stipules ca. 1 × 0.25 mm, densely villous with brown trichomes; tendrils villous or pubescent. Leaves elliptic to ovate-elliptic; petioles (9–)10(–16) mm, pubescent to villous with brown trichomes and sometimes also white trichomes; leaf blades (3.5–)4.5–5(–7) × (2–)2.5–4.5(–5) cm, discolorous; secondary veins alternate, 7 to 8 pairs, reaching and following the margin; tertiary veins apparent, 1 or 2 pairs, sometimes arising near the base of the lowest secondary vein, reticulation obscure; abaxial surface pale green, villous with white trichomes, and with occasional long brown trichomes present on the midrib and on the secondary veins, margin entire; midrib and secondary veins prominent; adaxial surface finely and sparsely villous, with longer white trichomes on veins; margin entire; base rounded; apex acute to shortly attenuate, with a short apiculus bearing a tuft of long ovatetrichomes. Inflorescences somewhat lax, pubescent with whitish trichomes, (4.5–)6–8(–14) cm, consisting of glomerules subtended by stipulelike bracts; glomerules generally pedunculate, (1–)4 mm, sometimes sessile, white-villous, 4- to 8-flowered; bracts densely pubescent on the outer surface with pale brown trichomes, glabrous on the inner surface, caducous, (1–)2 × ca. 0.5 mm; flowers apparently protandrous, borne on (2–)3(–4) mm, villous pedicels. Hypanthium broadly obconic, ca. 1 × 1.5 mm, becoming subglobose as the capsule develops; sepals ca. 1 × 1 mm, pale yellow, outer surface villous, inner glabrous; Manongarpetals ca. 1 × 0.25 mm, white; stamens slightly longer than petal, with a pale yellow filament and a pale yellow anther ca. 0.3 × 0.2 mm; disc flat, ca. 3 mm diam.; lobes ca. 0.25 mm, slightly recurved, rounded to shallowly emarginate or somewhat truncate, 1/4 as long as the sepals, young disc yellow, becoming pale yellow; stigma with 3 linear lobes, those ca. 0.4 mm, style ca. 0.5 mm. Fruits 0 to 2 developing on each glomerule, small (ca. 0.8 × 0.8 cm), spheroid, puberulous, equally distributed throughout the infructescence; valves ca. 8 × 4 mm; immature fruits with a yellow indument; seeds brown, shiny, ovoid and slightly flattened, ca. 3 × 2 × 1.5 mm.

Distribution and ecology

Gouania callmanderi grows in western and southwestern Madagascar (Fig. 2A). The new species can be found in semideciduous, deciduous, and xerophytic vegetation on limestone and sand at an elevation range from sea level to 1300 m.

IUCN Red List category

With an EOO of 296,807 km², an AOO of 279 km², and 22 known subpopulations, five of which occur within protected areas (Ampijoroa, Andohahela, Isalo, Manongarivo, Zombitsy), Gouania callmanderi is assigned a preliminary status of Least Concern (LC) according to IUCN Red List criteria (IUCN, 2001).

Phenology

This species has been observed flowering from October to March and fruiting from April to August.

Etymology

The species epithet was chosen by the first author in honor of Martin W. Callmander (1975–), Swiss botanist and co-author of this article, who introduced Sven Buerki to the Malagasy flora and supervised his M.Sc. dissertation, and in appreciation of his valued collaboration on numerous projects.

Discussion

This species is closest to Gouania ambrensis in the length of the pedicels and the whitish color of the inflorescence indument, but differs most notably in having elliptic to ovateelliptic, discolorous leaves (vs. ovate, concolorous in G. ambrensis), lobes of the disc about one fourth as long as the sepals (vs. lobes about one half as long), immature fruits with a yellow indument (vs. a brown to silver indument), and small fruits (ca. 0.8 × 0.8 cm vs. ca. 1.2 × 1.4 cm). Furthermore, G. callmanderi occurs throughout the west of Madagascar and is especially abundant in the southwest, whereas G. ambrensis is endemic to the Montagne d’Ambre in the extreme north of the island.

Paratypes

MADAGASCAR. Antsiranana: Manongarivo/Ambongo, [13°59′24″S, 48°22′12″E], H. Perrier de la Bâthie 6026 (P). Fianarantsoa: Vestiges forestiers à l’entrée d’Ihosy, 22°18′15″S, 46°16′43″E, S. Buerki, P. B. Phillipson & C. Rakotovao 55 (K, MO, P, TAN); Ihosy, [22°23′S, 46°07′E], J. Peltier & M. Peltier 2725 (TAN); rd. from Ihosy to Farafangana (9 km before Ihosy), 22°33′02″S, 46°32′36″E, P. De Block 1954 (BR, MO, P). Mahajanga: Antsianitia, 15°34′54″S, 46°25′14″E, M. W. Callmander & Phillipson 687 (G, K, MO, P, TAN); Ampijoroa, 16°19′S, 46°49′E, Phillipson 1929 (K, P, TAN, WAG); vic. of Lac Ampijoroa, [16°11′S, 47°06′E], A. Gentry 11456 (K, MO, P, TAN, WAG), Gentry 11487 (MO, P, TAN). Toliara: Forêt de Marosalaza, 50 km N de Morondava, [20°02′S, 44°33′E], J. P. Abraham 115 part A (K, P); Manasoa Tanosy, K. R. Afzelius s.n. (P); Lambomakondra, [22°42′S, 44°42′E], J. Bosser 28 (TAN); Masokara, plateau Mahafaly, Ankalirano, [20°02′S, 44°33′E], Bosser 14282 (TAN); Zombitsy PA, 22°52′43″S, 44°42′51″E, Buerki, Phillipson & Rakotovao 59 (BR, G, K, MO, P, S, TAN, US, WAG); Rte. d’Anjamala, [23°11′30″S, 43°57′30″E], F. Chauvet 441 (P, TEF); Zombitsy PA, [22°49′48″S, 44°41′24″E], T. B. Croat 30711 (MO, TAN); 23–43 km E of Tulear along rd. to Andranovory, [23°19′S, 43°56′E], Croat 31027 (MO, TAN, WAG); SW of Ampanihy on rte. to Androka betw. Ambanihy & PK 10, [24°45′S, 44°41′E], Croat 31392 (MO, TAN); Sakaraha, [22°54′S, 44°32′E], R. Decary 14104 (P); Morombe, [21°44′S, 43°21′E], Decary 18758 (P); Beroroha, [22°53′S, 44°14′E], Decary 18857 (P); Lambomakandro, [22°42′S, 44°42′E], Decary 18904 (P); Ranohira, [22°29′S, 45°24′E], Decary 18921 (P); Environs d’Ihosy, B. Descoings 2173 (TAN); Mandrare moyen, environs de Beza Esiva (Sud), [24°25′S, 46°32′E], Descoings 2741 (MO, TAN); ca. 20 km W of Ampanihy on rte. to Androka, 24°46′S, 44°36′E, D. J. Du Puy, J.-N. Labat & Phillipson MB610 (TAN); Zombitsy PA, off RN7, 22°52′S, 44°40′E, Du Puy, Labat & B. Rakouth MB654 (TAN); Vallée de la Manambolo, (bassin du Mandrare) au NW de Maroaomby (Betsioky), [24°21′20″S, 46°34′30″E], H. Humbert 12789 (G, P); Vallée de la Manambolo, rive droite (bassin du Mandrare) aux environs d’Isomono (confluent de la Sakamalio), [24°30′S, 46°37′E], Humbert 12985 (K, P, TAN); haute vallée de la Menarahaka à l’Est d’Ihosy, [22°32′30″S, 46°29′50″E], Humbert 28553 (P); Environs d’Antanimora (Androy), 30–35 km au N d’Ambia, [24°49′S, 45°40′E], Humbert 28814 (P); SW de Betioky près du trivillage d’Ankalirano, [24°13′S, 44°17′E], M. Keraudren 825 (P); RN7 at 15 km NE of Sakaraha, [22°96′S, 44°36′E], D. H. Lorence 1904 (K, MO); 54 km SW of Tulear, 23°13′S, 44°03′E, J. S. Miller & A. Randrianasolo 6169 (K, MO, P, TAN); Zombitsy PA, [23°53′00″S 44°40′00″E] P. Morat 680 (TAN); Plateau Mahafaly au NW d’Ejeda, [24°15′S, 44°05′S], Morat 4344 (P, TAN); 55 km NE of Morondava via rte. 8, 20°04′S, 44°40′E, R. D. Noyes, D. K. Harder, E. A. Rakotobe, T. G. Razafindrabeaza & J. P. Abraham 1051 (MO, P, WAG); bords de la Mahavavy/Ambongo, Perrier de la Bâthie 6024 (P); Zombitsy PA, 22°52′S, 44°31′E, Phillipson 3090 (K, MO, P, TAN, WAG); Ranobe Forest, 22°56′50″S, 43°41′08″E, P. B. Phillipson, R. Ranaivojaona, N. M. Andrianjafy & R. A. Lubke 5900 (G, K, MO, P, TAN, WAG); 5 km N of Beloha on RN10 to Ampanihy, 25°07′S, 45°06′E, P. B. Phillipson & J. R. Milijaona 3627 (G, K, MO, P, TAN, WAG); Andohaela PA, [24°40′12″S, 46°44′24″E], Réserves Naturelles 5201 (P, TAN), Réserves Naturelles 5949 (P, TAN); Environs d’Ampandrandava, [24°05′S, 45°42′E], A. Seyrig 214 B (P); Ampandrandava, Seyrig 369 (P).

4. Gouania cupreifolia Buerki, Phillipson & Callm., sp. nov. TYPE: Madagascar. Toliara: Vallée de la Manambolo, rive droite (bassin du Mandrare) aux environs d’Isomono (confluent de la Sakamalio), Mont Morahariva (Mahamena-Marovato), 1000–1400 m, Dec. 1933 (fl.), H. Humbert 13288 (holotype, P!; isotype, G!). Figure 5.

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Figure 5

Gouania cupreifolia. —A. Habit. —B. Leaf. —C. Flower, showing the lobes of the disc slightly shorter than or as long as the sepals. —D. Fruit. A–C drawn from the type Humbert 13288 (P); D from Homolle 2595 (P).

Haec species a congeneris madagascariensibus foliis in sicco abaxialiter cupreis ad marginem leviter recurvatis, disci lobis sepalis paullo brevioribus vel ea aequantibus atque fructibus parvis pubescentibus secus inflorescentiam sparsim dispositis facile distinguitur.

Woody liana climbing to 15 m; stems pale to dark green, drying gray, partially glabrescent with brown trichomes persisting on the ridges, young shoots sparsely pubescent with brown trichomes; stipules glabrate, (1–)2 × ca. 0.75 mm; tendrils pubescent. Leaves ovate, coriaceous; petioles gray, 12–15(–20) mm, sparsely pubescent with brown trichomes; leaf blades (4–)4.5–5.5(–7) × (3–)3.5(–5) cm; secondary veins alternate, 5 to 6 pairs, not reaching the margin but following it; tertiary veins apparent, arising near the base of the lowest secondary veins, sometimes absent, reticulation scalariform; abaxial surface glabrous, sparsely pubescent on the veins, a distinct coppery color when dried; midrib, secondary veins, and tertiary veins prominent; adaxial surface glabrous; margin entire, slightly recurved; base rounded to shallowly cordate; apex acute. Inflorescences ± lax, pubescent with a brownish indument, (4.5–)5.5–6(–8) cm, consisting of glomerules subtended by stipulelike bracts; glomerules sessile, shortly pedicellate, up to 1.5 mm long at the base of the inflorescence, 5- to 6-flowered; bracts small, densely pubescent on the outer surface with reddish trivillage chomes, glabrous on the inner surface, (0.5–)1 × ca. 0.25 mm; flowers pedicellate, pedicels (1–)2 mm, covered with a whitish indument. Hypanthium obconic, becoming subglobose as the capsule develops; sepals ca. 1.25 × 0.75 mm, pale brown, outer surface sparsely pubescent, inner glabrate; petals ca. 0.75 × 0.2 mm, pale brown, sometimes yellow; stamens slightly longer than the petal blades, with a pale brownish filament and a pale yellow, globulose anther ca. 0.2 × 0.2 mm; disc flat, ca. 2 mm diam.; lobes ca. 0.8 mm, triangular-lanceolate, 2/3 or as long as the sepals; stigma with 3 linear lobes, those 5–8 mm, style ca. 3 mm. Fruits solitary on the glomerule, small, oblong (ca. 0.7 × 1 cm), pubescent with brown trichomes, scattered throughout the infructescence; valves ca. 7 × 5 mm; immature fruits not seen; seeds brown, shiny, pyriform, and slightly flattened, ca. 2.5 × 2 × 0.5 mm.

Distribution and ecology

Gouania cupreifolia grows on the eastern escarpment of Madagascar (Fig. 2B). It can be found in sclerophyllous and deciduous vegetation at elevations of 800–1400 m.

IUCN Red List category

With an EOO of 37,956 km², an AOO of 45 km², and only five subpopulations, two of which occur within protected areas (Andohahela National Park, Betampona Nature Reserve), Gouania cupreifolia is assigned a preliminary status of Vulnerable (VU B2ab[ii]) according to IUCN Red List criteria (IUCN, 2001).

Phenology

Gouania cupreifolia has been observed flowering from December to January and fruiting in January.

Etymology

The new species epithet refers to the unusual, somewhat coppery color of the undersurface of the dried leaves.

Discussion

Gouania cupreifolia differs from all Malagasy species by the abaxial surface of its leaves drying to an unusual, somewhat coppery color, and the slightly recurved margins of the blade. Based on floral morphology, it appears to be most closely related to G. laxiflora, having the lobes of the discs slightly shorter than or as long as the sepals (ca. 0.8 mm long).

Paratypes

MADAGASCAR. Toamasina: Ankaroka, [17°48′S, 48°32′E], G. Cours 234 (P); Forêt d’Ankiribiry, Cours 2598 (P); Betampona PA, Anjiro en descendant ruisseau, Ranomena, [17°55′S, 49°13′E], A. M. Homolle 2595 (P). Toliara: bassin de réception de la Mananara, affluent du Mandrare, pentes occidentales des montagnes entre l’Andohahela et l’Elakelaka, mont Apiky au-dessus de Mahamavo, [24°45′30″S, 46°43′30″E], H. Humbert 13855 (P); Ampandrandava, [24°05′S, 45°42′E], A. Seyrig 369 (P), 369 bis (P).

5. Gouania cupuliflora Buerki, Phillipson & Callm., sp. nov. TYPE: Madagascar. Antsiranana: Ambanja, Ramena River, Chute d’Ambobaka, 13°44′48″S, 48°31′37″E, 40 m, 28 Feb. 2005 (fl.), S. Buerki & S.Wohlhauser 29 (holotype, MO!; isotypes, G!, K!, P!, TEF!). Figure 6D–G.

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Figure 6

A–C Gouania lineata. —A. Fruiting branch showing the dense infructescence of small fruits. —B. Fruit. —C. Leaf showing the lack of conspicuous tertiary veins. D–G. Gouania cupuliflora. —D. Young pyriform fruit. —E. Inflorescence showing the sessile glomerules composed of sessile cupulate flowers, and the lobes of the disc reaching two thirds the length of the sepals. —F. Infructescence. —G. Leaf, abaxial surface. A drawn from Morat 4454 (TAN); B, C from Gentry 11471 (TAN); D from Perrier de la Bâthie 6015 (TAN); E from the holotype Buerki & Wohlhauser 29 (MO); F, G from Derleth 62 (TAN).

Gouania mauritiana Lam. var. angustiloba H. Perrier, Notul. Syst. (Paris) 11: 34. 1943, nom. nud.

Haec species a congeneris madagascariensibus glomerulis sessilibus inter se distantibus ex floribus sessilibus cupulatis constantibus, disci lobis longitudine 2/3 sepalorum partes attingentibus, stigmatis lobis duobus linearibus atque fructu oblongo pubescente facile distinguitur.

Woody liana climbing to 3 m; stems dark green, drying blackish, densely pubescent with hirsute ferruginous trichomes; stipules densely pubescent with reddish brown trichomes, 2–3(–4) × ca. 0.75 mm; tendrils pubescent. Leaves ovate; petioles (5–)10–15(–20) mm, pubescent with ferruginous trichomes; leaf blades (3.5–)5.5(–6) × (1.5–)3 cm; secondary veins alternate, 7 to 9 pairs, reaching and following the margin; tertiary veins apparent, arising near the base of the lowest secondary veins, reticulation scalariform; abaxial surface sparsely pubescent with white trichomes; midrib, secondary veins, and tertiary veins prominent; adaxial surface sparsely pubescent with a fine white indument; margin entire; base rounded; apex acute to shortly attenuate. Inflorescences lax, pubescent with a brownish indument, (7–)11(–15) cm, consisting of well-spaced glomerules subtended by stipulelike bracts; glomerules sessile or shortly pedunculate, (3 to)8-flowered; bracts small, densely pubescent on the outer surface with a brownish indument, glabrous on the inner surface, caducous, (1–)2 × ca. 0.5 mm; flowers sessile, with a reddish indument. Hypanthium cupulate; sepals ca. 0.8 × 1 mm, whitish to pale yellow, the outer surface densely pubescent with reddish trichomes, the inner glabrous; petals ca. 1 × 0.5 mm, white; stamens slightly longer than the petal blades, with a pale yellow filament and a pale yellow, globulose anther ca. 0.2 × 0.2 mm; disc flat, ca. 3 mm diam.; lobes ca. 0.5 mm, emarginate or somewhat truncate, 2/3 as long as the sepals; stigma with 2 linear lobes, ca. 0.2 mm, style ca. 0.4 mm. Fruits 0 or 1 developing on each glomerule, oblong, ca. 1.1 × 1 cm, pubescent to puberulent with a brownish indument, equally distributed throughout the infructescence; valves ca. 10 × 4 mm, shallowly emarginate at the apex and the base; immature fruits globose, with a dense, pale yellow indument; seeds brown, shiny, ovoid and slightly flattened, ca. 5 × 3 × 1 mm.

Distribution and ecology

Endemic to northwestern Madagascar (Fig. 2C), Gouania cupuliflora occurs on sandy substrates and on limestone at elevations between 30 and 500 m, mainly in evergreen lowland rainforest, or in dry forest along rivers.

IUCN Red List category

Gouania cupuliflora has an EOO of 121,012 km² and an AOO of 207 km², with 20 known subpopulations, six of which occur within protected areas (Ampijoroa, Ankarafantsika, Ankarana, Bemaraha, Manongarivo, Namoroka). It is thus assigned a preliminary status of Least Concern (LC) according to IUCN Red List criteria (IUCN, 2001).

Phenology

Gouania cupuliflora has been observed in flower from January to April and in fruit from May to November.

Etymology

The new species is named for its markedly cupulate flowers.

Discussion

Perrier de la Bâthie referred material of this species to Gouania mauritiana var. angustiloba in his 1943 revision for the family (mentioned under G. mauritiana subsp. aphrodes). The varietal name was not accompanied by a Latin description or diagnosis and is therefore not validly published, according to the ICBN (McNeill et al., 2006: Art. 36.1). The varietal epithet chosen by Perrier de la Bâthie (1943) refers to narrow lobes of the disc relative to the other elements he included in G. mauritiana, but this name is not particularly appropriate in the context of the genus as a whole. We regard the taxon as a distinct species that we name G. cupuliflora in reference to its cupulate hypanthium. Gouania cupuliflora is allied to G. ambrensis, but differs by its sessile flowers covered outside by a ferruginous indument (vs. pedicellate flowers covered by silver trichomes in G. ambrensis), the cupulate hypanthium (vs. obconic hypanthium), the lobes of the disc reaching two thirds as long as the sepals (vs. lobes of the disc reaching one half of the sepals), and the stigma with two linear lobes (vs. the stigma 3-lobed).

Paratypes

MADAGASCAR. s. loc., fl., R. Baron 4680 (K, P); fl., R. Rakoto 18 (TAN); fl., Service Forestier 13 (P). Antsiranana: Ankarana, M. Bardot-Vaucaulon 1537 (K, MO, P, TAN); Chute d’Ambobaka, affluent de la Ramena, 13°44′50″S, 48°31′36″E, M. W. Callmander 286 (G, K, MO, P, TEF); entre Vohémar et Ambilobe, R. Decary 14659 (P); Besinkara, chemin d’Ambodisakoana à Ambalafary, P. Derleth 62 (G, K, MO, P, TAN); Daraina, forêt d’Ambilondomba, 13°10′S, 49°39′E, L. Gautier 4269 (G); Besinkara, Ambalafary, 14°04′S, 48°17′E, Gautier & S. T. Be 2883 (G, K, TAN, TEF); 3–5 km E of Diego-Suarez-Ambilobe Rd., 7 km N of Ambilobe, [13°11′30″S, 49°03′30″E], A. Gentry 11917 (MO, P, TAN); Ankarana PA, ca. 5 km NW of Park Village near Besaboba Stream, 12°51′16″S, 49°17′30″E, D. K. Harder, M. C. Merello, S. G. Razafimandimbison & T. G. Razafinfrabaeza 1762 (MO, P, TAN, WAG); Tsaratanana, région O de Majunga, R. P. Heydel s.n. (P); Vallée de Sambirano, H. Perrier de la Bâthie 6015 (P, TAN); Ambohimarina, plaine du Sambirano, 13°54′21″S, 48°29′21″E, Wohlhauser 60006 (G, TEF); Bassin versant de rano Bemahalegny, moyen Ambahatra, cours moyen du bassin-versant rano Ambahatra, 13°57′51″S, 48°26′56″E, Wohlhauser 60046 (G, MO, TEF). Mahajanga: Analafaly, Fokontany Bemanevika, Analafaly forest, 6 km E of Marotaolana, 17°13′10″S, 46°59′42″E, C. Birkinshaw & N. M. Andrianjafy 1500 (MO, P, TAN); Ouest environs de Maevatanana, près d’Ambodiroka, pont de la Betsiboka, [17°01′S, 47°45′E], B. Descoings 3301 (TAN); Ampijoroa STF, ca. 3 km N d’Andranofasika, 16°20′S, 46°51′E, L. G. Dorr & L. Koenders 3014 (K, P, TAN, WAG); Mailaka, région du Cap St. André, H. L. Douillot s.n. (P); Bemaraha massif, base of escarpment, ca. 10 km W of Marerano on Manambolo River, 19°04′S, 45°04′E, B. Du Puy, D. Du Puy, J. Andrianatina & B. Carlson MB730 (MO, P, TAN); Ampijoroa, 16°19′S, 46°49′E, Gentry & G. E. Schatz 62101 (TAN); Vallée de la Betsiboka, en amont de Maevatanana, [16°57′S, 46°50′E], H. Humbert 4442 bis (P); 10 km E Antsalova, at edge of the Tsingy of Bemaraha, [18°39′S, 44°37′E], J. Klackenberg 93.03.11–9 (MO, P); Bemaraha PA, [18°39′S, 44°37′E], J. D. Leandri 861 (P); Ambodiriana (Antsiafabositra), [15°55′S, 47°29′E], J. Peltier & M. Peltier 5183 (P); Amborovy, [15°39′30″S, 46°20′30″E], Peltier & Peltier 5297 (P); Morofotra, rive gauche de l’Ikopa en face de Maevatanana, Perrier de la Bâthie 6025 (P); moyen bassindu Bemarivo, Boina, [15°55′S, 47°40′E], Perrier de la Bâthie 6045 (P); Ampasimatera, bassin moyen de Bemarivo (Boina), [15°56′S, 47°44′E], Perrier de la Bâthie 6052 (P); Boina, Perrier de la Bâthie 14647 (P, TAN); Marosakoana, Réserves Naturelles 5 (P); Namoroka PA, [16°29′S, 45°22′E], Réserves Naturelles 5094 (P), Réserves Naturelles 6385 (P, TAN), Réserves Naturelles 6416 (P, TAN); Canton Andranomavo, distr. Soalala, Réserves Naturelles (Randriamera) 10144 (P, TEF); Ankarafantsika PA, Service Forestier 6 (P); Ampijoroa, [16°18′S, 46°49′E], Service Forestier 29760 (TEF).

6. Gouania gautieri Buerki, Phillipson & Callm., sp. nov. TYPE: Madagascar. Antsiranana: Besinkara, chemin entre Ambalafary et Ambosepals disakoana, 14°04′S, 48°17′E, 350 m, 26 Mar. 1996 (fl.), L. Gautier & S. T. Be 2904 (holotype, G!; isotypes, K!, P!, TAN!, TEF!). Figure 7.

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Figure 7

Gouania gautieri. —A. Immature fruits. —B. Habit. —C. Elliptic, glabrous leaf. —D. Flower, showing its cupulate form and the lobes of the disc reaching two thirds the length of the sepals. —E. Fruit, showing hirsute indumentum. —F. Seed. A–D drawn from Rabenantoandro et al. 197 (P); E, F from Gautier & Chatelain 2647 (TAN).

Haec species a congeneris madagascariensibus foliis glabris membranaceis ellipticis usque ovatis, inflorescentia trichomatibus brunneis hirsuta, glomerulorum pedunculis saepe dichotomis, floribus cupulatis subsessilibus, disci lobis longitudine 2/3 sepalorum partes attingentibus, fructu magno trichomatibus brunneis hirsuto atque semine ovoideo pallide brunneo facile distinguitur.

Woody liana climbing to 8 m; stems dark green, drying dark green to gray, glabrescent, young shoots pubescent, with brown trichomes; stipules glabrous, 2(–3) × ca. 0.75 mm; tendrils glabrescent. Leaves elliptic to ovate, blade rather membranous; petioles (7–)10–12(–20) mm, glabrous; leaf blades (5.5–)6.5–7(–11) × (2–)3.5(–5.5) cm; secondary veins alternately arranged, 4 to 5 pairs, not reaching the margin but following it; tertiary veins apparent, arising near the base of the lowest secondary veins, reticulation scalariform; abaxial surface glabrous; midrib, secondary veins, and tertiary veins slightly prominent; adaxial surface glabrous; margin entire; base rounded; apex acute. Inflorescences lax, (3–)4–5(–8) cm, pubescent with brown hirsute trichomes, consisting of glomerules subtended by stipulelike bracts; glomerules with a thick, often dichotomously branched peduncule, up to 3 mm, 4(to 8)-flowered; bracts caducous, (1–)2 × ca. 0.25 mm, puberulous on both surfaces with brownish caducous trichomes; flowers shortly pedicellate, pedicels ca. 1 mm, pubescent with brown trichomes. Hypanthium cupulate; sepals ca. 3 × 1 mm, pale yellow to brown, outer surface pubescent, inner glabrous; petals ca. 1 × 0.5 mm, pale yellow; stamens completely included in the petal blades, with a pale yellow filament and a pale yellow, globose anther ca. 0.2 × 0.2 mm; disc flat, ca. 5 mm diam.; lobes ca. mm, acute, 2/3 as long as the sepals; stigma with short linear lobes, style ca. 0.5 mm. Fruits 0 to 2 developing on each glomerule, oblong, large (ca. 1.5 × 1 cm), with a pale brown indument, equally distributed throughout the infructescence; valves ca. 15 × 3 mm; immature fruits globose, with a pale brown indument; seeds pale brown, ovoid, emarginate at apex, hardly flattened, recurved with a line on the inner surface, ca. 7 × 4 × 0.5 mm.

Distribution and ecology

Gouania gautieri is endemic to the Manongarivo massif, northwestern Madagascar (Fig. 2C), at an elevational range of 350–1300 m. This species seems to be restricted to degraded forest.

IUCN Red List category

With an EOO of less than 227 km², an AOO of 27 km², and two subpopulations, one of which occurs within a protected area (Manongarivo PA), Gouania gautieri is assigned a preliminary status of Endangered (ENB1ab[ii]; B2ab[ii]) according to IUCN Red List criteria (IUCN, 2001).

Phenology

Gouania gautieri is known in flower from September to March, and in fruit at the beginning of April.

Etymology

The new species is named in honor of Laurent Gautier (1960–), Swiss botanist, who has greatly contributed to the knowledge of the flora of the Manongarivo massif and who collected the type specimen.

Discussion

Gouania gautieri resembles G. cupuliflora in having a cupulate hypanthium and the lobes of the disc two thirds as long as the sepals, but differs most notably in having elliptic to ovate, membranous, glabrous leaves (vs. ovate, subcoriaceous, pubescent with ferruginous trichomes in G. cupuliflora); a congested inflorescence (vs. lax); glomerules often with dichotomously branched peduncles (vs. unbranched peduncles); and hirsute pale brown indument on the fruits (vs. pubescent to puberulent with a darker brown indument).

Paratypes

MADAGASCAR. Antsiranana: Fiv. Ambanja, Fir. Ambodimanga-Ramena, 13°48′49″S, 48°47′22″E, J. Rabenantoandro, C. Birkinshaw, B. Razafindrazaka, P. Antilahimena & F. Adamainty 197 (G, K, P, MO); Besinkara, au-dessous d’Ambalafary, 14°04′S, 48°17′E, L. Gautier & C. Chatelain 2647 (G, K, P, TAN); Manongarivo PA, Antsatroto, 14°05′S, 48°23′E, S. Malcomber, P. J. Rakotomalaza & J. Raharilala 2287 (MO).

7. Gouania humbertii H. Perrier, Notul. Syst. (Paris) 11: 29. 1943. TYPE: Madagascar. Antsiranana: collines et plateaux calcaires de l’Analamerana, 50–400 m, Jan. 1938 (fl.), H. Humbert 19233 (holotype, P!; isotypes, G!, TAN!).

Woody liana; stems dark green, drying blackish, glabrous, rather spindly; stipules glabrous, 2.5(′3) × ca. 1 mm; tendrils puberulent with caducous ferruginous trichomes. Leaves orbicular, often con-duplicate; petioles to 12 mm, glabrous at maturity; leaf blades (2.5–)3(–3.5) × (2–)3(–3.5) cm; secondary veins alternate, 4 to 5 pairs, not reaching the margin but following it; conspicuous tertiary veins absent, reticulation scalariform; abaxial surface Madaglabrous; midrib and secondary veins slightly prominent; adaxial surface glabrous; margin entire, slightly recurved; base rounded; apex acute. Inflorescences congested, puberulent, spindly, (2.5–)3(–4.5) cm, consisting of glomerules subtended by stipulelike bracts; glomerules shortly pedunculate, to 1 mm, 3(to 5)-flowered; bracts small, glabrous on both surfaces, (0.5–)1 × ca. 0.2 mm; flowers pedicellate up to 1 mm, glabrous at maturity. Hypanthium cupulate; sepals ca. 1.5 × 0.75 mm, pale brown, outer surface puberulent, inner glabrous; petals ca. 1 × 0.2 mm, pale yellow to brown; stamens slightly longer than the petal blades, with a pale yellow filament and a pale yellow, globose anther ca. 0.2 × 0.2 mm; disc flat, ca. 2 mm diam.; lobes ca. 1.25 mm, rounded, generally 3/4 or as long as the sepals; stigma with 3 linear lobes, ca. 0.2 mm; style ca. 0.2 mm. Fruits not known.

Distribution and ecology

Gouania humbertii is endemic to the semi-deciduous to decidous forests of northern Madagascar. It has not been recollected at the type locality, Analamerana PA (formerly known as Analamera), but was recently discovered at Daraina (about 50 km to the southeast) (Fig. 2D). The taxon grows on limestone or granitic rocks at an elevational range of 50–400 m.

IUCN Red List category

With only two collections and an AOO of 18 km², Gouania humbertii is regarded as Endangered (EN B2ab[ii]), according to IUCN Red List criteria (IUCN, 2001).

Phenology

This species has been collected in flower during January.

Discussion

Gouania humbertii shares a lack of conspicuous tertiary veins with G. lineata and a cupulate hypanthium with G. cupuliflora and G. gautieri. Nevertheless, this species can be distinguished from these two and all other Malagasy species by its orbicular, often conduplicate, glabrous leaves and the lobes of the disc reaching three fourths or as long as the sepals. Gouania humbertii is the only species known from semi-deciduous to deciduous forests of the Plateau d’Analamerana and is unlikely to be confused with other species occurring in the Daraina forests.

Additional specimen examined

MADAGASCAR. Antsiranana: Daraina, partie sud de la forêt de Bekaraoka, 13°11′S, 49°42′E, Nusbaumer 2050 (G).

8. Gouania laxiflora Tul., Ann. Sci. Nat., Bot. sér. 4, 8: 130. 1857, as “Guania.” TYPE: Madaglabrous; gascar. Antsiranana: Ling-Vatou, s.d. (fr.), A. Bernier 207 (lectotype, designated here, P!). Figure 8A, B.

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Figure 8

A, B. Gouania laxiflora. —A. Fruiting branch showing the infructescence with glabrous fruits concentrated at the base. —B. Flower showing the lobes of the disc reaching or extending beyond the sepals. C–E. Gouania myriocarpa. —C. Fruiting branch showing the infructescence with dense small fruits. —D. Flower showing the lobes of the disc reaching one sixth the length of the sepals. —E. Fruits. A drawn from Buerki et al. 63 (TAN); B from Perrier de la Bâthie 6030 (P); C from the type Goudot s.n. (G); D from Humbert 7021 (P); E from Buerki et al. 46 (TAN).

Gouania comorensis Engl., Veg. Erde 9: 315. 1921, nom. nud., in obs.

Gouania glandulosa Boivin ex Tul. var. longiloba H. Perrier, Notul. Syst. (Paris) 11: 31. 1943, nom. nud.

Gouania lineata Tul. var. recurviloba H. Perrier, Notul. Syst. (Paris) 11: 30. 1943, nom. nud.

Gouania leguatii J. Guého, Adansonia 18(4): 483. 1979, syn. nov. TYPE: Rodrigues Island. Cascade Victoire, Feb. 1941 (fl.), R. Jauffret 129 (holotype, MAU not seen; isotype, P!).

Gouania mozambicensis M. L. Green, Bull. Misc. Inform. Kew 1916: 199. 1916, syn. nov. TYPE: Mozambique, Chupanga, 1860 (fr), Kirk s.n. (holotype, K!).

Woody liana climbing to 4 m; stems dark green, drying brown, glabrescent, young shoots pubescent with ferruginous trichomes; stipules glabrous, 1(–1.5) × ca. 0.25 mm; tendrils pubescent with caducous ferruginous trichomes. Leaves ovate with a cordate or rounded base; petioles (15–)25(–35) mm, sparsely pubescent with caducous ferruginous trichomes; leaf blades (4.5–)6(–7.5) × (3–)4.5(–5.5) cm; secondary veins alternate, 5 to 8 pairs, not reaching the margin but following it; tertiary veins apparent, arising near the base of the lowest secondary veins, reticulation scalariform; abaxial surface glabrescent, veins puberulous with brown trichomes; midrib, secondary veins, and tertiary veins prominent; adaxial surface glabrous; margin synentire to slightly denticulate; base cordate or sometimes rounded; apex acute. Inflorescences spindly, lax, puberulous with pale brown trichomes, (5.5–)10–13(–15) cm, consisting of glomerules subtended by stipulelike bracts, proximal hermaphrodite flowers developing before the distal male flowers; glomerules pedunculate, puberulent with caducous, pale brown trichomes, accrescent, (1–)3 mm, 3- to 5-flowered; bracts small, glabrous on both surfaces, caducous, (0.5–)0.8 × ca. 0.2 mm; flowers pedicellate, pedicels accrescent, (1–)3.5 mm, puberulent with caducous, pale brown trichomes. Hypanthium obconic, becoming subglobose as the capsule develops; sepals ca. 2 × 0.75 mm, pale yellow to brown, outer surface puberulent, inner glabrous; petals ca. 1 × 0.5 mm, white; stamens slightly longer than the petal blades, with a pale yellow filament and a pale yellow, globose anther ca. 0.2 × 0.2 mm; disc flat, ca. 4 mm diam.; lobes 2–2.2 mm, rounded, generally longer or as long as the sepals; stigma with 3 linear lobes, those ca. 0.2 mm, style ca. 2 mm. Fruits 0 to 2 developing on each glomerule, spheroid (ca. 1.5 × 1.5 cm), glabrous, concentrated in the basal part of the infructescence; valves ca. 15 × 4 mm; immature fruits pyriform, glabrous; seeds brown, shiny, and slightly flattened on the inner surfaces, ca. 4 × 3 × 1 mm.

Distribution and ecology

Gouania laxiflora is found in mainland Africa (Mozambique and Tanzania) (Drummond, 1966; Johnston, 1972: under G. scandens, see discussion below), the Mascarenes (Rodrigues Island), the Seychelles (Aldabra, Île Picard, Cosmoledo), the Comoro Islands (Mayotte), and western Madagascar (Fig. 2D). The species grows in semi-deciduous, deciduous, gallery, and secondary forests, generally on limestone, but sometimes on sand and gneiss at an elevational range from sea level to 350 m.

IUCN Red List category

Within Madagascar, Gouania laxiflora has an EOO of 430,841 km², an AOO of 360 km², and 33 subpopulations, 13 of which occur within protected areas (Andohahela, Ankarana, Bemaraha, Beza Mahafaly, Namoroka, Tampoketsa d’Analamaitso, Zombitsy). It is thus assigned preliminary status of Least Concern (LC) in Madagascar, according to IUCN Red List criteria (IUCN, 2001). We have not assessed its conservation status for other countries within its range.

Phenology

This species has been collected in flower from November to March and in fruit in March and May.

Discussion

Tulasne (1857) designated two synentire types of Gouania laxiflora, Boivin 3366 and Bernier 207. The sheet labeled Boivin 3366 at P is a collection of this species, while sheets with the same collection number at G and K bear material of G. aphrodes. To avoid possible confusion, we have lectotypified this species on Bernier 207, even though material of this collection is only known to be present at P.

After careful study, we are convinced that this plant is conspecific with Gouania leguatii described from Rodrigues Island (Guého, 1997). Material referred to this species has similar cordate leaves, pubescent with caducous ferruginous trichomes, the disc lobes generally as long as or longer than the sepals, and the fruits glabrous and generally concentrated in the basal part of the infructescence. The same is true for the specimens cited in Flora Zambesiaca (Drummond, 1966) and in Flora of Tropical East Africa (Johnston, 1972) under G. scandens from the African mainland (see also discussion under G. scandens). Gouania longipetala Hemsl. was described for an African species, based on two syntypes from Equatorial Guinea or Gabon (Mann 17 from Bioko Island “Fernando Po” and Mann 1813 from Muni River “Kongui River”) and one, Kirk s.n., from Chupanga, Mozambique (Hemsley, 1868). Green (1916) realized that this material represents two different species and described G. mozambicensis to accommodate the East African entity based on the Kirk specimen, while retaining the name G. longipetala for the Central African species. Later Hallé (1962) designated Mann 17 from Bioko as the “Type,” thus effecting lectotypification of G. longipetala. Kirk’s specimen from Mozambique is a specimen of G. laxiflora, and we include G. mozambicensis in the synonymy of this species. Gouania laxiflora is the only species shared between mainland Africa and Madagascar.

Gouania laxiflora differs from G. perrieri, to which it is most similar, by its slightly denticulate leaf margin (vs. shallowly crenate margin in G. perrieri), lobes of the disc as long as or longer than the sepals (vs. lobes of the disc reaching one fourth of the sepals), and its immature pyriform fruits (vs. immature fruits winged).

Additional specimens examined

COMORO ISLANDS. s. loc., fl. & imm. fr., Boivin s.n. (K). Mayotte: Grande Terre, Mtsamboro, Ilot Mtsamboro, Barthelat et al. 198 (P); Grande Terre, Mamoudzou, Ilt Bouzi, Barthelat et al. 355 (G, K, MO, P); Boeni, Boivin 3366 (P); Coconi, Lorence 2818 (MO); Chissioi Caroni (islet off SW coast), Lorence Roulleau 2814 (MO); Dapani, Pascal 568 (P); Chissious Mtsamboro, près du sommet, Pignal & Pibot 1183 (K, P); Baie de Langoni, Tinguy 1019 (P). MADAGASCAR. s. loc., “Central Madagascar,” fl., Baron 3532 (K), fl., Baron 4815 (K), fr., Baron 4819 (K, P); fl., Baron 4823 (K); fl., Greve 107 (G, P). Antsiranana: Ankarana PA, campement des anglais, Andrianantoanina et al. 841 (P); Ankarana PA, Matsaborimanga, piste Grim, Bardot-Vaucaulon et al. 1170 (K, MO, P, TAN); Ankarana PA, Bardot-Vaucaulon 1549 (K, MO, P, TAN); Daraina, Forêt de Bekaraoka, Gautier al. 4368 (G); Collines et Plateaux calcaires de l’Ankarana, Humbert 18822 (P), Humbert 18907 (G, P, TAN), Humbert 32437 (P); Ankarana PA, near Campement des Anglais, Leuwenberg et al. 14329 (K, MO, P, TAN, WAG); Montagne d’Ambre, versants ouest, Gautier et al. 5251 (G, K, MO, TEF); Montagne d’Ambre, Razanajatovo et al. 30 (G, MO, P, TEF); Montagne des Français, Perrier de la Bâthie 17523 (P); Ankarana PA, Randriambololona et al. 36 (P). Fianarantsoa: Rte. Ihosy-Ivohibe, Km 40, Peltier & Peltier 5585 (P). Mahajanga: Sakoany, Callmander & Phillipson 697 (G, K, MO, P, TAN, US, WAG); Forêt d’Ambanjabe, Cours 3951 (P, TAN); Plateau d’Ankaro, Descoings 3368 (TAN); Morondava, Grevé s.n. comm. Dr Baillon (K); Fore d’Ambanjabe, Mont Marovoay, Herb. Inst. Sci. Madag. 3951 (TAN); Rte. d’Ambato-Boeni, Jacquemin 912 (P); Fore d’Analamaitso, Keraudren 1703 (P); Bemaraha PA, Leandri 576 (P); Bemaraha PA, Leandri 580 (P), Leandri 863 (P), Leandri 932 (MO, P), Leandri 940 (P), Leandri 968 (P), Leandri s.n. (P); Vers Ambodiriana, Leandri 2704 (P); Rte. de Majunga, P.K. 538, Morat 2719 (P, TAN); Namoroka PA, Morat 4809 (P, TAN); Amdriba (RN27), Peltier & Peltier 5755 (P); Bois le long du Jabohazo, Antririhitra près de Mont Tsitondraina, Perrier de la Bâthie 1590 (K, P); Marofotra, rive gauche de l’Ikopa en face de Maevatanana, Perrier de la Bâthie 6027 (P), Perrier de la Bâthie 6029 (P); Mariarana près du Mont Tsitondroina (Boina), Perrier de Bâthie 6028 (P); environs d’Amboina près de Majunga, Perrier de la Bâthie 6030 (P); en chemin de Maevatanana, Perrier de la Bâthie 6039 (P); Boina, Perrier de la Bâthie 14647 (P); Antsalova, Réserves Naturelles 11107 (P); Soalala, Réserves Naturelles 2138 (P, TAN); Namoroka PA, Service Forestier 11-SF (P); environs de Berivotra, Service Forestier (Capuron) 162 (P); Antsalova, Service Forestier 19840 (TEF); Berano, Service Forestier 26518 (PTEF); Amboina, Sol 34 (P); 14 km E of Antsalova, Villiers et al. 4777 (K); 12 km ESE Ankiliromotsy, 26 km SE Antsalova, Villiers et al. 4997 (K, P). Toliara: Manasoa Mahafaly, Afzelius s.n. (MO, P); S of Andranovory, betw. Ambatry & Toboky Mitsy, Anderberg, Smedmark, Axelius, Manns & Englund 166 (P, S); [25 km NE of] Andranovory, Andriamahay et al. 560 (K); Mahabo, Andriamahay et al. 820 (P); Befandiana-Sud, Appert 68 (K, WAG); Ankilizato (Mont Mahabo), Bosser 4611 (TAN); après Mahaboboka allant à Toliara, Buerki et al. 63 (K, MO, P, TAN); 23– km E of Tulear along rd. to Andranovory, Croat 31059 (K, MO); Rte. Nationale 10 betw. Tongobory & Betioky, Croat 31232 (MO); RN10 betw. Ejeda & Ampanihy, betw. PK 200 & 250, Croat 31339 (MO, TAN); 1–4 km W of Etrobecke, Croat 31448 (MO, TAN); along Rte. 13 from Ambovombe Antanimora, Croat 32015 (MO, TAN); Ambovombe (Mont Angavo), Decary 8610 (P); ferme de Mahabo, Dequaire 27034 (P, TAN); Sud Ambovombe, Descoings 1464 (MO, TAN); Manombo, Douliot s.n. (P); 12 km SW of Ampanihy on rte. to Androka, Du Puy & Du Puy MB579 (TAN); Mahafaly plateau, ca. 7 km S of Beahitse on RN10, Du Puy et al. MB36 (TAN); ca. 17 km N of Ejeda on Rte. Nationale 10, Du Puy et al. MB608 (TAN); Fiherenena, Geay 3345 (P); Morondava, Grevé 111 (K, P, TAN); Gorges du Fiherenana entre Beantsy et Anjamala, Humbert 19909 (P); de la vallée de la Sakamena à la vallée de la Sakoa (bassin de l’Onilahy), Humbert 29409 (P); RN7 at 98 km NE of Tulear, 400 m, Lorence 1920 (TAN); Rte. Ankazoabo, Morat 2908 (TAN); Piste Ankazoabo après le village de Laborano, Morat 3580 (P, TAN); 55 km NE of Morondava via rte. 8, Kirindy Forest, Noyes et al. 1052 (P, WAG); Beza Mahafaly PA, parcelle 1, Phillipson 1687 (K, MO, P, TAN); 64 km along RN55 from Morombe, Mangoky valley, Phillipson et al. 4140 (P); Analamaiky, Rakotondranony et al. 212 (K); Ranobe Forest, Phillipson et al. 5880 (G, K, MO, P, TAN, WAG); Andohahela PA, parcelle 3, Randriamampionona 272 (P, WAG); Andohahela PA, parcelle I, Randriamampionona 808 (P). MASCARENE ISLANDS. Rodrigues Island: Balfour s.n. (K, P), Jauffret 105 (P); Cascade Momoac, Lesouef s.n. (P). (African specimens examined are not listed). SEYCHELLES. Aldabra. West Island (Île Picard): back of settlement, 2–3 m, Fosberg 48699 (K, MO), Fosberg 48806 (MO), Fosberg 48831 (K, MO), Fosberg 49499 (MO); coast N of settlement just S of Anse Var, Fosberg 49484 (K); settlement, Renvoize 715 (K); near settlement, Stoddart 967 (K); 50 m E of laboratory, Wood 1610 (K); no precise locality, Abbott s.n. (K), Dupont 12 (K), Dupont 129 (K), Fryer 76 (K), Renvoize 1362 (K), Thomasset 231 (K). Cosmoledo: Thomasset s.n. (K).

9. Gouania lineata Tul., Ann. Sci. Nat., Bot. sér. 4, 8: 131–132. 1857, as “Guania.” TYPE: Madagascar. Antsiranana: Nosy Be, Lokobe, (“Nossibé, Forêt de Loucoubé ”), [13°25′S, 48°19′E], Dec. 1850 (fr.), L. H. Boivin 2171/2b (lectotype, designated here, P 00386419!; isotype, P 00386420!). Figure 6A–C.

Woody liana climbing to 4 m; stems green, drying dark brown, glabrescent, young shoots puberulous with pale trichomes; stipules glabrous, 2(–3) × ca. 0.75 mm; tendrils puberulous. Leaves ovate to elliptic; petioles (5–)10–15(–20) mm, glabrous; leaf blades (4–)5.5(–12) × (2–)3.5(–6) cm; secondary veins alternate, 6 to 7 pairs, not reaching the margin but following it; conspicuous tertiary veins absent, reticulation scalariform; abaxial surface glabrous, veins puberulous with pale trichomes; midrib and secondary veins prominent; adaxial surface glabrous; margin entire, slightly recurved; base rounded; apex acute. Inflorescences congested, pubescent with a white indument, (5.5–)8.5(–12) cm, consisting of glomerules subtended by stipulelike bracts; glomerules sessile, sometimes shortly pedunculate at the base of the inflorescence, 2(to 5)-flowered; bracts pubescent with pale trichomes on the outer surface, glabrous on the inner surface, caducous, (1.5–)2 × ca. 0.5 mm; flowers pedicellate, pedicels accrescent, (1–)2.5 mm, pubescent with whitish trichomes. Hypanthium obconic, becoming subglobose as the capsule develops; sepals ca. 1.5 × 0.5 mm, pale yellow, outer surface pubescent, inner glabrous; petals ca. 1 × 0.5 mm, pale yellow; stamens slightly longer than the petal blades, with a pale yellow filament and a pale yellow, globose anther ca. 0.2 × 0.2 mm; disc flat, ca. 3 mm diam., pale yellow to white; lobes ca. 0.5 mm, acute to slightly truncate, 1/3 as long as the sepals; stigma with 3 linear lobes, those ca. 15 mm; style ca. 2 mm. Fruits 1 to 2 developing on each glomerule, small, oblong (ca. 0.5 × 1 cm), glabrous, densely arranged throughout the infructescence; valves ca. 5 × 5 mm; immature fruits globose, puberulous with whitish trichomes; seeds brown, shiny, ovoid to pyriform and slightly flattened, ca. 3 × 2 × 0.5 mm.

Distribution and ecology

Gouania lineata occurs in western and northern Madagascar (Fig. 2B) in evergreen, semi-deciduous forests and secondary vegetation on sand or limestone at an elevational range from sea level to 900 m.

IUCN Red List category

Based on an EOO of 309,667 km², an AOO of 207 km², and 21 subpopulations, eight of which occur within protected areas (Ankarafantsika, Isalo, Manongarivo, Namoroka, Tsaratanana, Zombitsy), we assign Gouania lineata a preliminary status of Least Concern (LC), according to IUCN Red List criteria (IUCN, 2001).

Phenology

Gouania lineata is known in flower from January to May and in fruit from June to January.

Discussion

Gouania lineata is based on multiple syntypes with specimens only known to be present at P. One of these collections, Pervillé 617, is represented by two sheets, and the other, Boivin 2171/2, is represented by three sheets. The Pervillé collection from “Ambongo” is dated 15 February 1841 and clearly represents a single gathering, both sheets bearing specimens with similar very young inflorescences with no open flowers or fruits. The three Boivin sheets represent two separate gatherings, presumably put together later under a single number (possibly explaining the dual number “2171/2” that appears on each of the sheets, but see the note below about Boivin 2171). The first of the sheets (P00386418) bears a flowering specimen and an original label with the information: “Nossi-Cumba.juill. 1850. fr. / Nossibé, Forêt de Loucoubé, mars 1851. fl.,” together with a Paris Herbarium label with the printed information “Madagascar, Voyage de M. Boivin, 1847–1852,” on which the name G. lineata, the reference to the Tulasne (1857) publication, and the collection number are handwritten. The other two sheets of Boivin 2171/2 each bear similar Paris Herbarium labels bearing exactly the same printed and handwritten information as the first sheet, but lack original labels with the collection locality or date. One of these sheets (P 00386418) bears a specimen with mature fruits and old infrutescences; the second (P 00386420) bears a specimen that is almost sterile, bearing no fruits and just a few flowers on a highly reduced inflorescence. We conclude that these flowering and fruiting specimens correspond to the two gatherings noted on the original label that is present on the first sheet. To distinguish the gatherings, we designate the fruiting collection (“fr.”) from Nosy Kumba (“Nossi-Cumba”) as Boivin 2171/2a and the flowering collection (“fl.”) from Lokobe Forest on Nosy Be (“Nossibé, Forêt de Loucoubé”) as Boivin 2171/2b. We select the better of the two Nosy Be specimens, which bears the original label, as the lectotype. It should be noted that Boivin also collected the type specimen of G. aphrodes at Nosy Be under the number 2171.

Gouania lineata is morphologically most similar to G. myriocarpa Tul.; both species possess small glabrous fruits congested along the entire infructescence. However, G. lineata can be distinguished from G. myriocarpa by the lack of conspicuous tertiary veins on its leaves and by the lobes of the disc reaching one third of the sepals (vs. lobes of the disc reaching one sixth of the sepals). Furthermore, while G. lineata is widespread in western Madagascar, G. myriocarpa is confined to the eastern escarpment and the central plateau.

Additional specimens examined

MADAGASCAR. s. loc., fl., Boivin s.n. (K); fl., Service Forestier 9 (P, TAN). Antananarivo: forest remnant betw. Ambaranala & Tsiroanomandidy, Barnett et al. 399 (K, P, TAN); Rebord occidental Bongolava, O Tsiroanomandidy, Morat 4597 (P, TAN). Antsiranana: Mandrizavona, Antsahafaly River, Antilahimena 419 (G, MO, P, TAN); Nosy Kumba (“NosiCumba”), Boivin 2171/2a (P); Andranosavony, Buerki & Wohlhauser 34 (K, MO, P, TEF); Besinkara, Gautier et al. 2401 (G, K, TAN); Saharenana, Sadjoavato, Forêt de Sahafary, Hongwa et al. 205 (Centre National d’Application de Recherche Pharmaceutique [CNARP], MO, P); Ambipresumably lobe, Ambakirano, Behefaka, Anjahana, forêt de Belifilelatra, Hongwa et al. 309 (CNARP, MO, P, TAN); Ambilobe, Forêt Ambohibe, Leopold et al. 120 (MO, P, TAN); Massif du Manongarivo, Perrier de la Bâthie 1552 (P), Perrier de la Bâthie 6042 (P); Daraina, Forêt d’Antsahabe-nord, Ranirison 767 (G, MO); Bemanevoka, Ambobaka, Ratovoson et al. 193 (G, MO, P, TAN); Ambodisakoana, Totozafy Be 552 (G, P). Fianarantsoa: Isalo, Homolle 1462 (P); environs d’Ihosy, Humbert 14464 (P); Ihosy, Peltier & Peltier 4887 (P). Mahajanga: Antsianitia, Callmander & Phillipson 677 (G, K, MO, P, TAN, US); Namoroka PA, Decary 18981 (P); vic. of Lac Ampijoroa, Gentry 11471 (K, P, TAN); Bongolava de Port Bergé, Morat 4454 (P, TAN); Boina, Perrier de la Bâthie 6037 (P); Ankarafantsika PA, Perrier de la Bâthie 14694 (K, P, TAN); Vallon de Mangotroky, près Soalala (Ambongo), Perrier de la Bâthie 1552 bis (P); Ambongo, Pervillé 617 (P); Namoroka PA, Réserves Naturelles 8648 (P, TEF); Lac Ampijoroa, Service Forestier (Rabevohitra) 29773 (TEF). Toliara: Zombitsy PA, Allorge 2110 (P); Zombitsy PA, Croat 30720 (MO, TAN); E of Tulear betw. 45 & 55 km E of Tulear on rd. to Andranovory, Croat 31070 (MO, TAN); Plateau gréseux à l’Est de la vallée Sikily au NW d’Ankazoabo, Humbert 29725 (P); Forêt de Marosalaza, Petter 30, 32 (P); Zombitsy PA, Randrianaivo et al. 305 (P).

10. Gouania mauritiana Lam., Encycl. 3: 5. 1789. TYPE: Mauritius (cultivated). Cultivée au Jardin vegetadu Roi, s.d. (st.), Herbier Lamarck s.n. (lectotype, designated here, P-LA!). EPITYPE: Réunion. Mare sèche, Cilaos, 24 Jan. 1983, T. Cadet 6500 (epitype, P 00386378!).

Gouania incisa Vahl, Symb. Bot. (Vahl) 3: 101. 1794, nom. superfl.

Gouania sericea Hils. ex C. Presl, Abh. Königl. Böhm. Ges. Wiss., ser. 5 39, 1844, nom. superfl.

Gouania sericea Sieber ex Tul., Ann. Sci. Nat., Bot. sér. 4, 8: 134. 1857, nom. inval. (ICBN, Art. 34.1a).

Woody liana; stems dark green, drying brown to ferruginous, densely lanate with ferruginous trichomes; stipules pubescent with a ferruginous indument on the upper surface and glabrous on the inner surface, (4–) 5(–6) × ca. 3 mm; tendrils pubescent. Leaves lanceolate to deltoid; petioles (8–)10(–15) mm, densely pubescent with a ferruginous trichome; blade (3.5–)4.5–5(–6) × (2.5–)3.5(–4) cm; secondary veins alternate, (5 to)6(to 7) pairs, reaching and following the margin; tertiary veins apparent, 5(to 7) pairs, arising near the base of the lowest secondary veins, fine reticulation obscure; abaxial surface lanate with whitish trichomes on the limb, and ferruginous trichomes on the midrib, secondary veins, and tertiary veins; adaxial surface pubescent with appressed whitish trichomes; margin serrate; base rounded to shallowly cordate; apex acuminate. Inflorescences ± lax, densely pubescent with a reddish indument, (5.5–)6–7(–8) cm, consisting of compact glomerules subtended by stipulelike bracts; glomerules sessile, up to 15-flowered, glomerules at the base of the inflorescence; bracts triangular-lancelolate, densely pubescent with reddish trichomes on the outer surface and glabrous on the inner, ± persistent, (5–)6 × ca. 2 mm; flowers shortly pedicellate, pedicels ca. 1.5 mm, covered by a whitish indument. Hypanthium obconic, becoming subglobose as the capsule develops; sepals ca. 1.5 × 2 mm, pale yellow, outer surface densely pubescent with whitish trichomes at the base and reddish trichomes at the apex, inner glabrous; petals ca. 1 × 0.25 mm, whitish; stamens partially included in the petal blades, with a pale yellow filament and a pale yellow, globose anther ca. 0.2 × 0.2 mm; disc flat, ca. 2.5 mm diam.; lobes ca. 0.4 mm, slightly emarginate, 1/4 as long as the sepals; stigma with 3 linear lobes, those ca. 0.75 mm, style ca. 1 mm. Fruits 1 developing on each glomerule, oblong (ca. 1 × 1.2 cm), glabrous, densely arranged; valves ca. 10 × 5 mm; immature fruits globose, with a whitish indument, becoming reddish when mature; seeds pale brown, ovoid and slightly flattened, ca. 3.5 × 2 × 0.5 mm.

Distribution and ecology

Endemic to Réunion Island, Gouania mauritiana is found in humid, evergreen montane rainforest and secondary vegetation at an elevational range of ca. 1000 m.

IUCN Red List category

Gouania mauritiana has only been collected at one locality (Cilaos) on Réunion Island in the past 100 years, and only one older collection can be accurately georeferenced. Neither locality is in a protected area, so with an AOO of 18 km² the species is regarded as Endangered (EN B2ab[ii]), according to IUCN Red List criteria (IUCN, 2001).

Phenology

This species has only been collected in fertile condition (flower and fruit) in January.

Discussion

Gouania mauritiana was described by Lamarck based on a plant cultivated in the Jardin du Roi in Mauritius. However, when he chose the epithet he had not seen specimens from Réunion Island where the species is native, and he was apparently unaware that the plant did not originate from Mauritius. Although there can be no doubt about the identity of the type specimen, it is sterile; we, therefore, select a modern specimen, Cadet 6500, which bears both flowers and fruit, to serve as an interpretative epitype.

In this treatment we adopt a much narrower concept of Gouania mauritiana than Perrier de la Bâthie (1943, 1950). Herein we limit G. mauritiana to the typical subspecies and recognize the three other subspecies (G. mauritiana subsp. aphrodes, G. mauritiana subsp. myriocarpa, and G. mauritiana subsp. pannigera) at the rank of species, as established by Tulasne in 1857. Gouania mauritiana differs from these species by its lanceolate to deltoid leaves (vs. ovate in the other three), the abaxial surface covered by woolly whitish trichomes (vs. a beige indument in G. aphrodes, but glabrescent in G. myriocarpa, and whitish or grayish indument in G. pannigera), its disc lobes reaching one fourth of the selength of the sepals (vs. lobes of the disc reaching one sixth of the sepals in G. aphrodes, G. myriocarpa, and G. pannigera). Furthermore, G. mauritiana appears to be endemic to Réunion Island, whereas G. aphrodes occurs in Madagascar and the Comoro Islands, and G. pannigera and G. myriocarpa are endemic to Madagascar.

Additional specimens examined

RÉUNION ISLAND. s. loc., Barclay s.n. (K); fl. & imm. fr., Boivin 1383 (P); fl., Boivin s.n. (K); fr., Commerson s.n. (K, P); fl., De L’Isle 605 (P); fl., Du Petit Thouars s.n. (P); fl., Herb. Colonial ministère de la marine s.n. (P); fl., Hilsenberg s.n. (K); fl., Richard s.n. (P); Crête gauche du Bulon, au-dessus de Dattier, Boivin 1383/2 (G, K, P); Cilaos, Cadet 724 (P), Cadet 1831 (P).

11. Gouania myriocarpa Tul., Ann. Sci. Nat., Bot. sér. 4, 8: 132. 1857, as “Guania.” Gouania mauritiana Lam. subsp. myriocarpa (Tul.) H. Perrier, Notul. Syst. (Paris) 11: 33. 1943. TYPE: Madagascar. Toamasina: Ambanivoules, côte orientale, s.d. (fr.), J. P. Goudot s.n. (holotype, G!; isotype, G!). Figure 8C–E.

Gouania glandulosa Boivin ex Tul. var. breviloba H. Perrier, Notul. Syst. (Paris) 11: 32. 1943, nom. nud.

Woody liana climbing to 10 m; stems dark green, drying dark brown to black, tomentose with rather caducous ferruginous trichomes; stipules glabrous, 3(–4) × ca. 0.75 mm; tendrils pubescent. Leaves ovate; petioles (5–)10–15(–20) mm, pubescent with ferruginous trichomes; leaf blades (4.5–)5.5–6(–7) × (2.5–)3(–4) cm; secondary veins alternate, 4 to 5 pairs, not reaching the margin but following it; tertiary veins conspicuous, arising near the base of the lowest secondary veins, reticulation scalariform; abaxial surface glabrescent, pubescent with ferruginous trichomes on the veins; midrib, secondary veins, and tertiary veins treatprominent; adaxial surface glabrous; margin shallowly crenulate; base rounded, sometimes shallowly cordate; apex acute. Inflorescences congested, pubescent with hirsute ferruginous trichomes, (8–)12(–25) cm, consisting of glomerules subtended by stipulelike bracts; glomerules sessile or shortly pedunculate, (2 to)4-flowered; bracts scarious, small, glabrous on both surfaces, ± persistent, (1–)2 × ca. 0.5 mm; flowers with a spindly pedicel (1–)1.5(–2) mm, covered by a whitish indument. Hypanthium obconic, becoming subglobose as the capsule develops; sepals ca. 1.5 × 0.5 mm, reddish, outer surface pubescent to glabrous, inner glabrous; petals ca. 0.75 × 0.25 mm, reddish; stamens slightly longer than the petal blades, with a pale red filament and a pale red, globulose anther ca. 0.2 × 0.2 mm; disc flat, ca. 2 mm diam.; lobes ca. 0.25 mm, truncate or slightly emarginate, 1/6 as long as the sepals; stigma with 3 linear lobes, those ca. 0.8 mm; style ca. 1 mm. Fruits 1 or 2 developing on each glomerule, small, spheroid (ca. 0.6 × 0.6 cm), glabrous, densely arranged throughout the infructescence; valves ca. 6 × 4 mm; seeds brown, shiny, ovoid, ca. 2 × 1 × 0.3 mm.

Distribution and ecology

Gouania myriocarpa occurs in eastern Madagascar (Fig. 2D) in evergreen montane rainforest and secondary forests on basaltic rocks, gneiss, and laterite soils at an elevational range of (500–)800–100(–1400) m.

IUCN Red List category

With an EOO of 164,280 km², an AOO of 216 km², and 17 subpopulations, seven of which occur within protected areas (Andohahela, Anjanaharibe-Sud, Analamazoatra-Perinet, Marojejy, Masoala, Montagne d’Ambre, Ranomafana), Gouania myriocarpa is thus assigned a preliminary status of Least Concern (LC), according to IUCN Red List criteria (IUCN, 2001).

Phenology

This species is known in flower from November to February and in fruit from March to July.

Discussion

Tulasne described Gouania myrio-carpa together with six other species of Gouania in his treatment of the Rhamnaceae for Florae Madagascariensis (Tulasne, 1857). Later, adopting broad species concepts, Perrier de la Bâthie (1943) reduced three of these species (G. aphrodes, G. myriocarpa, and G. pannigera) to subspecies of G. mauritiana. We agree with Tulasne’s narrower delimitation and these taxa are again recognized at the species level.

Furthermore, Perrier de la Bâthie did not examine the type specimen of Gouania myriocarpa, citing “Ambanivola, Goudot (in Herb. Delessert, non vu)” (Perrier de la Bâthie, 1950: 46), and, as a result, he completely misinterpreted this taxon. In his treatments for G. mauritiana subsp. myriocarpa (Perrier de la Bâthie, 1943: 33; 1950: 46), he included specimens that we now refer to G. phillipsonii, which we describe as new below. On the other hand, he referred specimens of true G. myriocarpa to his new variety, G. glandulosa var. breviloba (Perrier de la Bâthie, 1943: 32; 1950: 43), a name that was not validly published.

Gouania myriocarpa is morphologically most similar to G. lineata, both having glabrous fruits congested along their entire infructescences (see G. lineata for further comparison). Gouania myriocarpa can, however, be recognized easily among the Malagasy species by the presence of the ferruginous trichomes on the petioles, along the veins of the abaxial leaf surface, and the inflorescence. The lobes of its floral disc are one sixth as long as the sepals, and the glabrous fruits are densely arranged on the infructescence.

Additional specimens examined

MADAGASCAR. s. loc., fl., Baron 239 (K, P). Antsiranana: Montagne d’Ambre PA, SE du Lac Texier, Debray H1341D (P); Anjanaharibe-Sud PA, Rasoavimbahoaka & Ravelonarivo 215 (P, TAN); Marojejy PA, Rasoavimbakoaka 566 (K, P, TAN); Anjanaharibe-Sud PA, Ravelonarivo & Rasovimbahoaka 74 (P, TAN, WAG); Montagne d’Ambre PA, Schledl 167 (TAN). Fianarantsoa: Iakora, forêt de Sakalava, Andrianjafy et al. 982 (MO, P, TAN); Ranomafana, bord de la route nationale, Buerki et al. 46 (BR, G, K, MO, P, TAN, US, WAG); Ambohimotombo, Forsyth-Major s.n. (G); haute vallée de la Rienana (bassin du Matitanana), Humbert 3626 (P, TAN); massif de l’Ivakoany, Humbert 7021 (P); Ranomafana PA, parcelle 3, Rakoto 392 (P); Analamanavaona, proche Vohimary, Rakotovao 652 (P); Andrambovato, Service Forestier (Capuron) 265 (P, TEF). Toamasina: Moramanga, Ambatovy, Antilahimena et al. 5297 (MO, P, TAN, TEF), Antilahimena et al. 5375 (MO, P, TAN, TEF), Antilahimena et al. 6085 (MO, P, TAN, TEF); Andranobe, SO du lac Alaotra, 1100 m, Bosser 19865 (MO, P, TAN); Ambatoharanana near Antsevabe, Cours 4050 (P, TAN); Bemainty, vers 850 m, Cours 4205 (P, TAN); Perinet PA, Cremers 1492 (P, TAN); along Rte. 2 betw. Perinet & Beforona, Croat 32330 (K, P, TAN); S de Moramanga, Decary 6911 (K, P); S de Moramanga, Decary 7123 (P, TAN); RN2 at 15 km W of Perinet, Lorence 2013 (P, TAN); Analamazoatra-Perinet PA, 1040 m, Lowry & Schatz 4304 (K, P, TAN, WAG); Ambohilero, logging rd. from Antserabe, 1120 m, Lowry et al. 6615 (MO, P, TAN); vic. of 13 km marker on mine rd. to Tsaravoniana encampment, Noyes et al. 990 (P, WAG); bords de Mangoro entre Beparasy et Moramanga, Perrier de la Bâthie 17199 (P); Rivière Sahanana, barrière du Sakaleony, Perrier de la Bâthie 6014 (P); Antananarivo on rd. to Perinet, Phillipson 1624 (K, P, TAN, WAG); Ambatovy, Rakotomalaza 1160 (P); Betampona PA, Réserves Naturelles 3672 (MO, P, TAN); Ambohitralanana, Réserves Naturelles 8814 (P, TAN); Perinet PA, Service Forestier 1422-SF (P, TAN, TEF); Ambodilongotra, Moramanga, Service Forestier 26772 (P, TEF); 12 km bifurcation entre rte. de Lakanto et Moramanga, Service Forestier 29722 (TEF). Toliara: Vohifeno, Beaujard 375 (P); montagnes gneissiques entre le col du Kalambatritra et la vallée de la Manambolo, affluent de l’Ionaivo, Humbert 12099 (P); Andohahela PA, Euanihilia, Réserves Naturelles 5157 (P).

12. Gouania pannigera Tul., Ann. Sci. Nat., Bot. sér. 4, 8: 134. 1857, as “Guania.” Gouania mauritiana Lam. subsp. pannigera (Tul.) H. Perrier, Notul. Syst. (Paris) 11: 33. 1943. TYPE: Madagascar. Antananarivo: bois aux environs de Tananarive, s.d. (fl. & imm. fr.), J. P. Goudot s.n. (holotype, G!; isotype, G[2]!). Figure 9E–H.

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Figure 9

A–D. Gouania perrieri. —A. Flower showing the lobes of the disc reaching one fourth of the way along the sepals. —B. Infructescence showing the glabrous fruits concentrated at the base. —C. Fruit. —D. Leaf, abaxial surface. E–H. Gouania pannigera. —E. Fruit. —F. Flower showing the lobes of the disc reaching one fourth of the way along the sepal. —G. Inflorescence. —H. Leaf, abaxial surface (in front), adaxial surface (behind). A drawn from Hildebrandt 3001 (P); B, C from Hildebrandt 3017 (P); D from Réserves Naturelles 4228 (P); E–H from Buerki & Phillipson 35 (TAN).

Woody liana climbing to 10 m; stems dark green, drying blackish, densely pubescent with a red-brown indument; stipules densely pubescent on the 2 surfaces with reddish brown trichomes, 2(–3) × ca. 1 mm; tendrils pubescent. Leaves ovate, discolorous when dried; petioles (6–)10(–15) mm, pubescent with a reddish brown trichome; leaf blades (3–)4–5(–7) × (2–)3(–3.5) cm, discolorous; secondary veins alternate, sometimes subalternate, 5 to 6 pairs, reaching and following the margin; tertiary veins apparent, 2(to 4) pairs, arising generally from the first pair of secondary veins, sometimes from the second, fine reticulation obscure; abaxial surface lanate with whitish or grayish indument; midrib, secondary veins, and tertiary veins covered by a whitish indument that becomes reddish when dried; adaxial surface pubescent with brown trichomes; margin entire, sometimes with 1 or 2 teeth near the base; base rounded; apex rounded or subacute. Inflorescences congested, densely pubescent with a reddish indument, (4–)7– 8(–12) cm; glomerules shortly pedunculate, peduncles up to 1.5 mm, 10-flowered; bracts densely pubescent, persistent, (2–)3 × ca. 1 mm; flowers and fruits shortly pedicellate, pedicels up to 1 mm, covered by a reddish indument. Hypanthium obconic, becoming subglobose as the capsule develops; sepals ca. 2 × 1 mm, pale yellow to whitish, outer surface densely pubescent, inner glabrous; petals ca. 1 × 0.25 mm, whitish; stamens totally included in the petal blades, with a pale yellow filament and a pale yellow, globose anther ca. 0.2 × 0.2 mm; disc flat, ca. 3 mm diam.; lobes ca. 0.3 mm, truncate or somewhat emarginate, 1/6 as long as the sepals; stigma with 3 linear lobes, those ca. 0.75 mm, style ca. 1 mm. Fruits 0 to 1 developing on each glomerule, oblong (ca. 1 × 1.4 cm), sparsely pubescent with reddish trichomes, equally distributed throughout the infructescence, only the distal flower of each glomerule develops to a fruit, the others falling and leaving conspicuous scars; valves ca. 10 × 7 mm; immature fruits globose, with a whitish indument that becomes reddish; seeds pale brown, ovoid and slightly flattened, ca. 4 × 3 × 1 mm.

Distribution and ecology

Gouania pannigera is distributed in central Madagascar (Fig. 2B) in evergreen montane rainforest and secondary forest on quartzite, sand, and basalt rocks at an elevational range of 800–1500 m.

IUCN Red List category

With an EOO of 215,709 km², an AOO of 360 km², and 34 subpopulations, six of which occur within five protected areas (Ambohitantely, Andringitra, Isalo, Tsaratanana, Zahamena), Gouania pannigera is thus assigned a preliminary status of Least Concern (LC) according to IUCN Red List criteria (IUCN, 2001).

Phenology

This species has been collected in flower from January to April and fruiting at the end of April.

Discussion

Gouania pannigera is morphologically most similar to G. aphrodes, G. mauritiana, G. phillipsonii, and G. taolagnarensis, all of which possess leaves with a dense indument and conspicuous tertiary venation on the adaxial surface, and most of which have sessile or shortly pedunculate flowering glomerules. However, G. pannigera is distinguished by its ovate leaves, the abaxial surface covered by a whitish or grayish indument and a reddish indument on the veins after drying; peduncle scars left by the flowers; and the presence of glomerules at the base of its infructescence. Furthermore, G. pannigera is distributed in the forests and disturbed areas in central Madagascar, whereas G. aphrodes is distributed in the north, G. phillipsonii is principally distributed in the eastern part of the island, and G. taolagnarensis in the southeast.

Perrier de la Bâthie (1943, 1950) treated Gouania pannigera as a subspecies of G. mauritiana allied to G. mauritiana subsp. aphrodes (see discussion under G. aphrodes) and G. mauritiana subsp. myriocarpa (see also discussion under G. myriocarpa), but we believe that the distinctive suite of characters demonstrated by G. pannigera, together with its coherent biogeography and ecological preferences, justify its reinstatement to species rank. Gouania pannigera was cited by Engler (1895: 265) from Gorongosa in Mozambique. We have not been able to trace the corresponding herbarium material, but we believe that this was simply a misidentification of a specimen of G. longispicata Engl., a form of which is found in that region with a particularly dense indument that resembles that of G. pannigera.

Additional specimens examined

MADAGASCAR. Antananarivo: Ilafy, Alleizette 607 (P), Alleizette 1204 (P); Central Madagascar, Baron 3971 (K); Tampoketsa d’Ankazobe, PK 120, Bosser 7808 (TAN); Ambohimanga, Bosser 12600 (TAN); Soarina, PK 22 rte. de Tananarive, Bosser 13802 (TAN); Ambohimanga, Colline royale, Buerki & Phillipson 35 (BR, G, K, MO, NY, P, TAN, US, WAG), 36 (G, K, MO, P, TAN, US, WAG); Ambohimanga, Colline royale, Buerki & Phillipson 37 (K, MO, P, TAN); Amboasary, bas de la montagne Behenjy, Buerki et al. 43 (BR, G, K, MO, NY, P, TAN, US, WAG); Ambohimanga, Decary 667 (P), Decary 6154 (P), Decary 6216 (G, P); Anosivato, Decary 6280 (P); Nord d’Ankazobe, Decary 7434 (P); Tampoketsa d’Ankazobe, Decary 19281 (P); Ambohimanga, Dequaire 27701 (P, TAN); Près d’Amboitromby, Descoings 3158 (TAN); Rocher d’Iaranandriana, Dorr et al. 2888 (K, MO, P, TAN, WAG); environs d’Antananarivo, Goudot s.n. (G); Ambohimanga, Herb. Jard. Bot. Tananarive 3262 (P); environs d’Andramasina, Leandri 3079 (P); Tampoketsa d’Ankazobe, près port forestier de la Manankaza, Keraudren 1153 (K); Ambohimanga, Parker s.n. (K); environs de Betafo, Perrier de la Bâthie 6013 (P); Ambohimanga, Perrier de la Bâthie 7057 (P); Mois-Chaîne de Betafo, 1300 m, Perrier de la Bâthie 13085 (K, P); Forêt alterd’Ampatsakandrainivavy, Randrianaivo et al. 518 (MO, P); Ambohitantely PA, Réserves Naturelles 1222 (P, TAN); Tampoketsa-Ankazobe, Schatz et al. 3949 (P, TEF); Tsinjoarivo, Service Forestier (Capuron) 4 (TEF); Andramasina, Service Forestier 67 (P); Ambohimanga, Waterlot 57 (P); Ankaratra, Waterlot 690 (P). Antsiranana: Tsaratanana PA, Réserves Naturelles (Rababoto) 5988 (P). Fianarantsoa: Andringitra, N-facing mtn. slopes in N part of Natl. Park, A. Anderberg, J. Smedmark, B. Axelius, U. Manns & M. Englund 65 (MO, P, S); Soaindrana, Buerki et al. 49 (BR, G, K, MO, P, S, TAN, US, WAG); Iaritseana, Buerki et al. 50 (BR, G, K, MO, NY, P, TAN, US, WAG); portion de 5 km anciennement goudronnée en face de la brioche, après Mahasoa, Buerki et al. 54 (BR, G, K, MO, NY, P, TAN, US, WAG); montée vers le plateau d’Horombe, Buerki et al. 56 (K, MO, P, TAN); PK 45 rte. Ivato à Ambatofinandrahana, Cremers 2062 (G, P, TAN); Inselbergs W of Ambalavao, at PK 475 near base of rock formation along creek, Croat 30187 (MO, TAN, WAG); environs Ambatofinandrahana, Decary 13172 (P); environs Ambatofinandrahana, Decary 13260 (P); RN5, Canton Sandrisoa, distr. Ambalavao, Henri 5532-RN (P); massif de l’Ivakoany, Humbert 7037 (P); Ihosy, base de la montée sur l’Horombe, Jacquemin 1261 (P); Isalo, rivière Sakamalio en aval de l’ancien village, Jacquemin H352J (P); Sandrandahy, bassin de la Mania, Peltier & Peltier 2196 (P); Antanifotsy, forêt de Ramiova et Ambodirina, Razafindrambao 745 (P); Ambalavao, Réserves Naturelles (Rabevazaha) 10382 (P); Ranohira, Service Forestier 13896 (P). Toamasina: Menaloha, Cours 680 (P); Ambatondrazaka, Decary 16441 (P); rte. de Vohidiale, Dequaire 27782 (P); ca. 9.5 km au NNW de Didy S rte. Ambatondrazaka, Gereau et al. 5763 (MO, P); Anony, Hb. Jard. Bot. Tananarive 2958 (P); Lac Alaotra, Homolle 580 (P); Ankazotokana, Réserves Naturelles (Ramanatsoavina) 1954 (P, TAN); Zahamena PA, Réserves Naturelles 3766 (P); Ankosy, Rakotovao 11039 (P). Toliara: Analavelona, Andriamihajarivo et al 1656 (MO, P, TAN); limite est de Zombitsy, bord de la Rte. Nat. 7, Buerki et al. 60 (K, MO, P, TAN); SE, Descoings 494 (TAN); Forêt d’Analavelona, Humbert 14231 (P).

13. Gouania perrieri Buerki, Phillipson & Callm., sp. nov. TYPE: Madagascar. Antsiranana: Ankarana PA, 12°56′S, 49°07′E, 100–300 m, 17–24 June 1993 (fr.), O. Andrianantoanina & R. Bezara 180 (holotype, MO!; isotypes, P!, TAN!), Figure 9A–D.

Gouania glandulosa Boivin ex Tul. var. sambiranensis H. Perrier, Notul. Syst. (Paris) 11: 32. 1943, nom. inval.

Haec species a congeneris madagascariensibus foliis glabris cordatis usque deltatis ad marginem leviter crenatis, floribus pedicellis longis (3–7 mm) insidentibus, disci lobis longitudine 1/4 sepalorum partem attingentibus atque fructu magno (ca. 1.5 × 1.5 cm) glabro facile distinguitur.

Woody liana; stems dark green, drying brownish to blackish, glabrous; stipules glabrous, 1(–1.5) × ca. 0.25 mm; tendrils glabrescent. Leaves cordate to deltoid; petioles 10(–20) mm, glabrous; leaf blades (4.5–)5.5(–6) × (3–)4.5 cm; secondary veins alternate, 5 to 6 pairs, not reaching the margin but following it; conspicuous tertiary veins absent or 2 to 3 pairs present but discrete, arising near the base of the lowest secondary veins, reticulation scalariform discrete; abaxial surface glabrous; midrib, secondary veins, and tertiary veins slightly prominent; adaxial surface glabrous; margin shallowly crenate; base cordate; apex acute to rounded. Inflorescences spindly, lax, glabrescent with hirsute pale trichomes, (3–)7(–9) cm, consisting of glomerules subtended by stipulelike bracts, the proximal flowers developing before the distal flowers; glomerules pedunculate, peduncles accrescent, (1–)3 mm, 2(–4)-flowered; bracts small, densely pubescent on the outer surface with reddish trichomes, glabrous, with a black line on the inner surface, caducous, 0.5(–1) × ca. 0.25 mm; flowers pedicellate, pedicels (3–)4(–7) mm, glabrescent at maturity. Hypanthium obconic, becoming subglobose as the capsule develops; sepals ca. 2 × 0.6 mm, pale yellow, outer surface puberulent, inner glabrous; petals ca. 1 × 0.5 mm, white; stamens slightly longer than the petal blades, with a pale yellow filament and a pale yellow, globose anther ca. 0.2 × 0.2 mm; disc flat, ca. 3 mm diam.; lobes ca. 0.5 mm, emarginate, 1/4 as long as the sepals; stigma with 3 very short linear lobes, style ca. 0.2 mm. Fruits 1 or 2 developing on each glomerule, spheroid, large (ca. 1.5 × 1.5 cm), glabrous, sometimes crenulate on the wings, often aggregated in the proximal part of the infructescence; valves ca. 15 × 10 mm; immature characfruits globose, puberulent; seeds brown, shiny, ovoid to pyriform and slightly flattened, ca. 3 × 2 × 0.5 mm.

Distribution and ecology

Gouania perrieri occurs in northern and western Madagascar, notably in the Sambirano region (Fig. 2A) in semi-deciduous and evergreen lowland forests on Tsingy limestone and basaltic rocks at an elevational range of 50–500 m.

IUCN Red List category

Based on an EOO of 59,374 km², an AOO of 700 km², and seven subpopulations, four of which occur within protected areas (Ankarana, Montagne d’Ambre, Namoroka), Gouania perrieri is thus assigned a preliminary status of Vulnerable (VU B1ab[ii]+2ab[ii]), according to IUCN Red List criteria (IUCN, 2001).

Phenology

The new species has been collected in flower from June to October and in fruit from February to May.

Etymology

This species is named in honor of Joseph Marie Henry Alfred Perrier de la Bâthie (1873–1958), French botanist, geologist, and outstanding explorer of Madagascar for over 30 years.

Discussion

Perrier de la Bâthie (1943) recognized this plant as a variety of Gouania glandulosa [≡ G. scandens subsp. glandulosa], but it differs by the crenulate margins of its leaves, the flowers with long pedicels (vs. sessile), the lobes of the disc reaching one fourth as long as the sepals (vs. the lobes longer, one third to two thirds as long as the sepals), and the large (ca. 1.5 × 1.5 cm) fruits, which are often aggregated on the basal part of the infructescence (vs. ca. 1 × 2 cm and more apically developed). Contrasting also in their distribution, G. perrieri is confined to semi-deciduous forest in northern and western Madagascar, while G. scandens subsp. glandulosa is typical of the humid forest of the east coast. The varietal name provided by Perrier de la Bâthie (1943) was not accompanied by a Latin description or diagnosis and was therefore not validly published according to the ICBN (McNeill et al., 2006: Art. 36.1).

Gouania perrieri is closest to G. laxiflora in the size and distribution of the fruits on the infructescence, but can be easily distinguished by the shallowly crenate leaf margins, the long pedicels, the lobes of the disc one fourth as long as the sepals, and its 3-winged immature fruits. It can be distinguished from other species in Gouania by its cordiform to deltoid, glabrous leaves with shallowly crenate margins; flowers with long pedicels; the lobes of the disc reaching one fourth as long as the sepals; and the large glabrous fruits concentrated on the basal part of the infructescence. This distinctive suite of characters justifies raising it to species rank.

Paratypes

MADAGASCAR. Antsiranana: Ankarana PA, 12°56′S, 49°07′E, O. Andrianantoanina & R. Bezara 180 (MO, P, TAN); Montagne des Français, 12°19′28″S, 49°20′28″E, M. Bardot-Vaucaulon 1776 (K, MO, P, TAN); Montagne d’Ambre PA, bord chemin proche camp des Roussettes, 12°31′28″S, 49°10′20″E, S. Buerki, M. W. Callmander & S. Wohlhauser 1 (MO, P); Bord de la rte. Sambava-Vohemar, PK 53, 13°40′33″S, 50°03′45″E, Callmander & Wohlhauser 249 (G, K, MO, P, S, TEF); Ankarana PA, 12°51′01″S, 49°13′30″E, D. K. Harder, M. C. Merello, S. G. Razafimandimbison & T. G. Razafindra-baeza 1750 (MO, TAN); Nosy Be, J. M. Hildebrandt 3001 (G, P); Norontsanga, [13°55′S, 47°55′E], J. M. Hildebrandt 3017 (K, P); Ankarana PA, 12°51′S, 49°05′E, M. Nicoll & J. P. Abraham 678 (K, MO, TAN, WAG); Montagne des Francçais, [12°20′S, 49°21′E], H. Perrier de la Bâthie 16322 (P); Amjiabe (Nosy Be), 13°04′50″S, 49°54′07″E, D. Rabehevitra, R. Razakamalala & T. Rakotomamonjy 226 (MO, P, TEF). Mahajanga: Namoroka PA, [16°29′S, 45°20′E], Réserves Naturelles 4228 (P), Réserves Naturelles 5620 (P, TAN); Namoroka PA, [16°29′S, 45°20′E], Service Forestier 3 (P).

14. Gouania phillipsonii Buerki, sp. nov. TYPE: Madagascar. Antananarivo: near Mahasoa, at the base of the Mandraka River, track to the E, 18°55′35″S, 47°55′50″E, 1060 m, 11 Nov. 2001(fl.), P. B. Phillipson & G. E. Schatz 5344 (holotype, MO!; isotypes, G!, GRA!). Figure 10.

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Figure 10

Gouania phillipsonii. —A. Fruit. —B. Flowering branch showing the broadly oval leaves with the first and second pairs of secondary veins widely spaced and the reptilian aspect of the adaxial surface. —C. Flower (lobes of the disc reaching one fourth of the way along the sepals). A drawn from Buerki et al. 42 (TAN); B, C from the type Phillipson & Schatz 5344 (MO).

Haec species ad Gouaniam pannigeram Tul. et G. taolagnarensem Buerki, Phillipson & Callm. maxime accedit, sed ab eis foliis parvis basaliter rotundatis margine subdenticulato ac venarum secundariarum paribus primo secundoque manifeste separatis, disci lobis longitudine 1/4 sepalorum partem attingentibus atque fructu juventute indumento luteo usque aurantiaco denso maturitate brunneo obtecto distinguitur.

Woody liana climbing to 15 m; stems dark green, protectdrying brown to dark gray, densely pubescent with hirsute reddish brown trichomes; stipules densely pubescent on the 2 faces with reddish brown Vulnertrichomes, 3(–4) × ca. 1 mm, ± persistent; tendrils pubescent. Leaves broadly ovate; petioles (5–)10–15(–20) mm, pubescent with brown trichomes; leaf blades (2.5–)3.5–4 × (1.5–)2.5 cm, discolorous; secondary veins alternate, the first pair oppositely arranged, 4 to 5 pairs, not reaching the margin but following it, with a larger space between the first and the third pairs, the second pair often reduced; tertiary veins apparent, (3 to)4(to 5) pairs, arising only from the first secondary veins, reticulation scalariform; abaxial surface densely villous with ferruginous to brown trichomes, ± uniform on the limb, midrib, and veins; midrib, secondary veins, tertiary veins, and reticulation prominent; adaxial surface sparsely puberulous with pale brown trichomes, finely bullate resembling reptile skin; margin sparsely denticulate, teeth with a reddish tuft of trichomes; base rounded; apex rounded or subacute. Inflorescences congested, densely pubescent with a reddish indument, (3–)4–7(–12) cm, consisting of glomerules subtended by stipulelike bracts; glomerules pedunculate, peduncles up to 3 mm, (4 to)8-flowered; bracts densely pubescent on both surfaces, persistent, (3–)4 × ca. 2 mm; flowers shortly pedicellate, pedicels up to 1.5 mm, covered by a brown indument. Hypanthium obconic, becoming subglobose as the capsule develops; sepals ca. 2.5 × 1.5 mm, pale yellow, outer surface densely pubescent, inner glabrous; petals ca. 1.5 × 0.75 mm, pale yellow; stamens totally included in the petal blades, with a white filament and a pale yellow, globose anther ca. 0.2 × 0.2 mm; disc flat, ca. 4 mm diam., pale yellow to white; lobes ca. 0.6 mm, thicker than the disc, truncate or somewhat emarginate, 1/4 as long as the sepals; stigma with 3 linear lobes, those ca. 0.3 mm, style ca. 1 mm. Fruits 0 or 1 developing on each glomerule, spheroid (ca. 0.8 × 0.8 cm), covered by a dense brown indument, equally distributed on the infructescence; valves ca. 8 × 4 mm; immature fruits globose, with a dense, pale-yellow to orange indument that becomes brown as the fruit matures; seeds pale brown, ovoid and slightly flattened, ca. 3 × 2 × 1 mm.

Distribution and ecology

Gouania phillipsonii grows on the eastern escarpment of Madagascar (Fig. 2A) in evergreen montane rainforest, on limestone and lateritic soils at an elevational range of 800–1100 m.

IUCN Red List category

Based on an EOO of 19,298 km², an AOO of 135 km², and nine subpopulations, seven of which occur within protected areas (Andringitra, Anjanaharibe-Sud, Mantadia, Perinet, Ranomafana, Zahamena), Gouania phillipsonii is thus assigned a preliminary status of Vulnerable (VU B1ab[ii]+2ab[ii]), according to IUCN Red List criteria (IUCN, 2001).

Phenology

The new species has been noted as flowering from May to November and fruiting from January to March.

Etymology

The species epithet was chosen by the first author in honor of Peter Phillipson (1957–), British botanist and co-author of this article, who made many important collections and observations of Malagasy Gouania since his first visit to Madagascar over 20 years ago. He was the co-supervisor of Sven Buerki’s M.Sc. research program.

Discussion

Perrier de la Bâthie (1943) was certainly familiar with this plant. He collected it himself at three different localities, citing these together with four other specimens under his Gouania mauritiana subsp. myriocarpa (Perrier de la Bâthie, 1943: 46). However, he did not see the type specimen, and it is clear that he completely misinterpreted Tulasne’s original description of G. myriocarpa (see discussion above under G. myriocarpa). No existing name is available for the species, which we describe here as new.

Gouania phillipsonii can be distinguished easily by its small broadly ovate leaves, the large space between the first and second pair of secondary veins, the slightly denticulate margin, the abaxial leaf surface with a rather uniform ferruginous to brown indument, and the adaxial surface that is finely bullate, giving it a distinctive aspect reminiscent of reptile skin. The lobes of the disc reach one fourth as long as the sepals, and the immature fruits have a dense yellow indument that becomes brown as the fruits mature.

Gouania phillipsonii is probably most closely related to G. aphrodes, G. pannigera, and G. taolagnarensis, which all have flowers with short disc lobes (less than one fourth the length of the sepals) and a relatively dense indument on their leaves. However, despite the diagnostic characters listed above, these species are not sympatric. Gouania phillipsonii occurs in forest mainly at mid-elevations on the eastern escarpment of Madagascar, whereas G. aphrodes occurs in the north at lower elevations, G. pannigera is known from the central region (often in degraded areas), and G. taolagnarensis is narrowly endemic to the region of Taolagnaro (Fort Dauphin) in the southeast.

Paratypes

MADAGASCAR. Antsiranana: Anjanahar-ibe-Sud PA, 14°32′45″S, 49°35′15″E, D. Ravelonarivo 195 (MO, P, TAN). Fianarantsoa: Ranomafana, en face du centre VALBIO, 21°15′14″S, 47°25′18″E, S. Buerki, P. B. Phillipson & C. Rakotovao 47 (G, K, MO, P, TAN); massif de l’Ikongo, [21°51′30″S, 47°26′30″E], R. Decary 5618 (P); Est Ivohibe, [22°29′S, 46°53′E], H. Humbert 3383 (G, K, P, TAN); Ranomafana PA, 21°15′S, 47°27′E, S. Malcomber, A. Leeuwenberg, C. Rakotomazaza, H. L. Raharijaona & G. Rahajasoa 1006 (G, K, MO, P, TAN, WAG); haute Rienana, bassin du Matitana, [22°13′29″S, 46°58′24″E], H. Perrier de la Bâthie 6022 (P); Ranomafana PA, just S of Namorona River, 21°16′S, 47°25′E, G. E. Schatz & J. S. Miller 2436 (K, P, TAN, WAG). Toamasina: Moramanga, [18°56′S, 48°12′E], K. R. Afzelius s.n. (MO, P); Moramanga, Ambatovy, Andasibe, Menalamba, Berano village, 18°50′45″S, 48°15′45″E, P. Antilahimena & F. Edmond 3956A (MO, P, TAN); Moramanga, Ambatovy, Andasibe, Menalamba, Ambovy forest, 18°51′38″S, 48°17′28″E, Antilahimena & Edmond 4088 (MO, P, TAN); Moramanga, Andasibe, Menalamba, rd. Analamay–Ambatovy, 18°50′24″S, 48°19′23″E, Antilahimena, J. Razanatsoa & Edmond 4219 (MO, P, TAN); Moramanga, Andasibe, Menalamba, Ambatovy forest, 18°51′29″S, 48°18′10″E, Antilahimena, M. Rabarimanarivo, Razanatsoa & Edmond 4303 (MO, P, TAN); Analamazaotra-Perinet, [18°56′S, 48°26′E], R. Benoist 1507 (P, TAN); Ambatovy, 18°52′10″S, 48°19′09″E, Buerki, Phillipson & Rakotovao 42 (BR, G, K, MO, P, TAN, WAG); Ambatoharanana, [18°00′S, 48°40′E], G. Cours 4118 (P); Sahamalaza, près du lac Alaotra, J.-M. Dequaire 27976 (P); La Mandraka, Hb. Jard. Bot. Tananarive 4468 (P); entre Mandritsara et Andilamena, Humbert 18059 (P); Analamazaotra-Perinet PA, [18°56′S, 48°26′E], M. Keraudren & G. G. Aymonin 25384 (P); near Andasibe, forest of Mantadia, 18°55′S, 48°25′E, G. McPherson & H. van der Werff 16486 (G, K, MO, P, TAN); forest N of Andasibe, 18°56′S, 48°25′E, Miller, J. Bradford, F. Rakotonasolo & A. Randrianasolo 8750 (TAN, WAG); River Anove, H. Perrier de la Bâthie 6016 (K, P, TAN); Analamazaotra-Perinet PA, [18°56′S, 48°26′E], Perrier de la Bâthie 6055 (K, P, TAN); Antsangimaso, Fokontany Ampitambe, Ambatovy, commune rurale Ambohibary, 18°51′05″S, 48°18′13″E, Razanatsoa, Antilahimena & Edmond 536 (MO, P, TAN); Moramanga, Ambohibary, Ampitambe, Forêt d’Ambohitavolo, 18°50′49″S, 48°17′17″E, Razanatsoa, Antilahimena & Edmond 162 (MO, P, TAN); Distr. Moramanga, Commune: Ambohibary, Fokontany: Ampitambe, Ambatovy, environ 22 km NE de Moramanga, 18°51′30″S, 48°18′16″E, Rakotovao, R. Razafindasy & Edmond 1443 (MO, TAN); Varaina, Réserves Naturelles 1593 (P); Forêt de Mantadia, 18°52.2′S, 48°29.8′E, F. L. van Nek 2015 (TAN, WAG).

15. Gouania scandens (Gaertn.) R. B. Drumm., Fl. Zambes. 2: 435. 1966. Basionym: Retinaria scandens Gaertn., Fruct. Sem. Pl. 2: 187, tab. 120, fig. 4. 1791. Retinaria volubilis Gaertn., Fruct. Sem. Pl. 2: 187, tab. 120, fig. 4. 1791. nom. superfl. Gouania retinaria DC., Prod. (DC.) 2: 40. 1825, nom. superfl. TYPE: [Mauritius.] Tab. 120, fig. 4 in Gaertner, 1791: 187 (lectotype, designated by Drummond [1966: 435, tab. 120, fig. 4] in Gaertner [1791: 187]).

Gouania tiliifolia Lam., Encycl. (Lamarck) 3: 5. 1789, as “tiliaefolia,” non Gouania tiliifolia Rottb. ex DC., 1825, nec Gouania tiliifolia Roxb., 1795 [ = Gouania microcarpa DC.]. TYPE: [Réunion Island.] Île Bourbon, s.d. (fl. & fr.), Commerson s.n. (lectotype, designated here, P-LA!; isotype, G!).

Woody liana climbing to a height of 15 m; stems dark green, drying brown to blackish, young shoots puberulent to pubescent with brown or red-brown trichomes, glabrous at maturity; stipules triangular to triangular-lanceolate, blackish, glabrous, ca. 3(–4) × (0.75–)2 mm, ± persistent or early caducous; tendrils sparsely pubescent, glabrescent. Leaves ovate to cordate; petioles dark brown, (8–)12–15(–20) mm, hirsute with caducous trichomes; leaf blades (4–)5–6(–8) × (2–)3(–4.5)cm; secondary veins alternately arranged, except the first pair opposite, 4 to 5 pairs, not reaching the margin but following it; tertiary veins apparent, 2 to 5 pairs, reticulation scalariform, conspicuous or not; abaxial surface glabrous or hirsute and glabrescent; adaxial surface glabrous; to margin crenulate or entire; base rounded shallowly cordate; apex acute to subacute. Inflorescences congested, puberulous or hirsute-glabrescent, (5–)7–14(–19) cm; glomerules sessile, lowest glomerules sometimes pedunculate; bracts triangular or lanceolate, glabrous or sparsely pubescent; flowers pedicellate, pedicels 3–5 mm. Hypanthium obconic, becoming subglobose as the capsule develops; sepals 2–2.5 × 0.8–2 mm, puberulent to glabrous outside, glabrous inside; petals 1–1.5 × ca. 0.5 mm, white to pale yellow; stamens about as long as the petals, pale yellow, with globose anther ca. 0.2 × 0.2 mm; disc flat, 3–4 mm diam.; lobes 0.5–1.5 mm, truncate to emarginate, 1/4 to 2/3 as long as the sepals; stigma with 3 linear lobes, 0.2–0.4 mm, style protruding from the disc. Fruits 0 or 1 developing on each glomerule, oblong (1–1.5 × ca. 2 cm), glabrous, with a curved pedicel; seeds pale to medium brown, ovoid and slightly flattened, 3–4 × 2–3 × ca. 0.5 mm.

Distribution and ecology

Gouania scandens occurs in Mauritius, Réunion Island, and Madagascar (east coast and Sambirano regions). It grows in evergreen lowland and montane rainforest, on limestone, sand, gneiss, and lateritic soils at an elevational range from sea level to 1100 m.

IUCN Red List category

Within Madagascar, Gouania scandens has an EOO of 148,427 km², an AOO of 306 km², and 27 subpopulations, eight of which occur encompassed within protected areas (Andringitra, Anjanaharibe-Sud, Betampona, Marojejy, Masoala, Zahamena). It is thus assigned a preliminary status of Least Concern (LC), in Madagascar according to IUCN Red List criteria (IUCN, 2001). We have not assessed its conservation status for other countries in which it occurs.

Distribution and ecology

Gouania scandens subsp. scandens occurs on Mauritius and Réunion in evergreen lowland rainforest at an elevational range of 200–600 m.

Phenology

This subspecies has been recorded in flower in January, May, and July and in fruit in April.

Discussion

Gouania scandens subsp. scandens is endemic to the Mascarenes. It is probably the only Gouania native to Mauritius. On Réunion it can easily be distinguished from G. mauritiana by its glabrous or at most sparsely pubescent vegetative parts (vs. densely pubescent). Furthermore, G. scandens subsp. scandens can be recognized by its cordiform, glabrous leaves, the crenulated margins with a black gland at the apex of every crenation, the lobes of the disc from 1/4 to as long as the sepals on the same flower, and the fruits with an arcuate pedicel, which tend to be rather equally distributed on the infructescence.

Additional specimens examined

MAURITIUS. s. loc., Ayres s.n. (K); Bojer s.n. (K); Commerson 626 (P); Commerson s.n. (K, P); Sieber fl. Mixta 208 (P); Sieber s.n. (G); forêts du quartier du grand Port, Boivin s.n. (P); Grand Port, and along the way to Vacoas, Bouton 5 (K); Long Montane, Bouton 65 (K); Piton du Fouge, mtn. range (E foot hills of ridge running toward Baie du cap), Guého 17901 (K, P); Perrier Natl. Reserve near Mare aux Vacoas, Lorence 2343 (K, MO, P); Bel Ombre Forest above Bon Courage, Lorence et al. 4494 (MO). RÉUNION ISLAND: s. loc., Commerson s.n. (G), Pourret s.n. (P), Richard s.n. (K). Ville Bague, Commerson s.n. (G, P).

15b. Gouania scandens subsp. glandulosa (Boivin ex Tul.) Buerki, Phillipson & Callm., comb. et stat. nov. Gouania glandulosa Boivin ex Tul., Ann. Sci. Nat., Bot. sér. 4, 8: 129. 1857, as “Guania.” TYPE: Madagascar. Toamasina: Sainte-Marie, 1834 (fr.), A. Bernier 239 (lecto-type, designated here, P!).

Gouania madagascariensis Rich. ex Tul., Ann. Sci. Nat., Bot. sér. 4, 8: 129. 1857, as “Guania,” nom. inval. (ICBN, Art. 34.1a).

Gouania sulcata Bojer, Hortus Maurit. 71. 1837, nom. nud.

Woody liana; stipules triangular-lanceolate, 3(–4) × ca. 0.75 mm, early caducous; tendrils sparsely glabrous at maturity. Leaves ovate; petioles dark brown, (8–)12–15(–20) mm, hirsute with caducous brown trichomes; leaf blades (4–)5–6(–7) × (2–)3– 3.5 cm; tertiary veins apparent, arising near the base of the lowest secondary veins, scalariform reticulation conspicuous; abaxial surface green to dark green, hirsute (and rough to the touch), glabrescent; midrib, secondary veins, and tertiary veins hardly prominent; margin generally entire, sometimes sparsely crenulate near the base and the apex; base rounded to shallowly cordate; apex acute. Inflorescences puberulous with pale pannose trichomes, (5–)7–9(–19) cm; glomerules sessile; bracts lanceolate, glabrous on both surfaces, (2–)2.5 × ca. 0.5 mm; pedicels up to 5 mm, densely puberulent with pale trichomes. Sepals ca. 2.5 × 2 mm, pale yellow to brown, outer surface puberulent to glabrous; petals ca. 1.5 × 0.5 mm, pale yellow; disc ca. 4 mm diam.; lobes emarginate or somewhat truncate, 1/3 to 2/3 as long as the sepals; stigma lobes ca. 0.2 mm, style ca. 3 mm. Fruits ca. 1 × 2 cm, mainly developed at the apex of the infructescence; valves ca. 10 × 10 mm; seeds brown, ca. 4 × 3 × 0.5 mm.

Distribution and ecology

Gouania scandens Antilahime subsp. glandulosa occurs in eastern Madagascar and the Sambirano region (Fig. 2C). It grows in evergreen lowland rainforest, on limestone, sand, gneiss, and lateritic soils at an elevational range of (0–)300–800(–1100) m.

Phenology

Gouania scandens subsp. glandulosa has been noted as flowering from November to April and fruiting from May to October.

Discussion

Gouania scandens subsp. glandulosa was treated by Tulasne (1857) and Perrier de la Bâthie (1943) as a distinct species, but we consider the similarity of this plant to typical G. scandens such that they should be regarded as conspecific. After examining the copious amounts of material available for both taxa, we have concluded that the small differences that do exist in the leaves and stipules and the slight differences in the variability in the size of the lobes of the disc are consistently correlated to geographic distribution. The Malagasy specimens can be distinguished from the Mascarene specimens on the basis of these characters, and we believe that subspecies rank is justified for these two allopatric taxa. Gouania scandens subsp. glandulosa can be distinguished easily from other species in Madagascar by its ovate leaves covered by hirsute caducous trichomes, a dark reticulation on the abaxial surface, the lobes of the disc one fourth to as long as the sepal on the same flower, and large, glabrous fruits concentrated at the apex of the infructescence.

The name Gouania madagascariensis appears on labels accompanying Richard’s specimens 186 and 335 from Madagascar. It was cited as a synonym of G. glandulosa by Tulasne (1857) but was never published as an accepted name, and is therefore nomenclaturally invalid. Gouania sulcata was published by Bojer (1837: 71), based on a Boivin collection from Madagascar, but the name lacks an adequate diagnostic description and is regarded as a nomen nudum. We include the Richard and Boivin specimens in question in G. scandens subsp. glandulosa.

Additional specimens examined

MADAGASCAR. s. loc., fl. & imm. fr., Baron 1114 (K, P); fl. & imm. fr., Baron 1443 (K, P); fl., Baron 2357 (K, P); imm. fr., Baron 2576 (K, P); “Central Madagascar,” Baron 2713 (K); fl., Boivin s.n. (P); fr., De Lastelle s.n. (P); fl., 1833, Goudot s.n. (G); fl. & imm. fr., Petit Thouars s.n. (P); Humblot 188 (K, P); fl. & fr., Richard 519 (P). Antsiranana: Masoala PA, Sahamalaza-Anovandrano, Bernard 137 (MO); massif of Tsihomanaomby, Birkinshaw 731 (P); Masoala PA, Cours 2199 (P, TAN); Daraina, forêt de Antsahabe, Gautier 4743 (G, MO); Baie de Diego-Suarez, Goudot s.n. (G); Vallée de la Lokoho (Nord-Est), Humbert 23243 (P); Vallée de l’Antsahabe, Humbert 23322 (P); Marojejy PA, Miller & Lowry 3892 (K, MO, P, TAN); Nossy-Mitsiou, Perrier de la Bâthie 18786 (P); Ambato, Rabenantoandro & Antilahimena 19 (P); Embouchure d’Ambohitralanana, presqu’île de Masoala, Rahajasoa 304 (P, WAG); Andapa, Anjiavabe, Rakotovao 3722 (MO, P, TAN); Marojejy PA, Rasoavimbahoaka 345 (K, MO, P, TAN); Anjanaharibe-Sud PA, Ravelonarivo et al. 776 (P, TAN); Ambondrobe, Razakamalala 1033 (P); Sambava, Bevontro, Tsaratanana, Morafeno, Forêt d’Antsahandroboka, Razakamalala et al. 3095 (MO, P, TAN); Marojejy PA, Réserves Naturelles 3954bis-RN (TAN); Ambohitralana, distr. Antalaha, Masoala PA, Réserves Naturelles 4446-RN (P, TEF); Vohemar, Richard 251 (P), Richard 335 (G, P); Marojejy PA, Service Forestier 17698-SF (P, TEF); Anjaniharibe-Sud PA, Tosh et al. 364 (G, BR, MO). Fianarantsoa: Mananjary, Geay 7234 (P), Geay 7366 (P, TAN), Geay 7367 (P), Geay 7368 (P), Geay 7694 (P), Geay 7723 (K, P); Ambalavao, Réserves Naturelles 8123-RN (P, TAN). Toamasina: Maraontsetra: Ambanizasuch na, Antilahimena et al. 1079 (MO, P, TAN); St-Marie, Bernier 268 (P), Boivin 1881 (P); PK 23 rte. de Tamatave, Bosser 13760 (MO, TAN); Fotimavo, Buerki 130 (G, K, MO, P, TAN); Nosy Mangabe, Carlson 180 (K, P, TAN); Antokazo, Cours 288 (P); Forêt d’Ambatosoratra, Cours 3375 (P, TAN); Brickaville, D’Arcy 15281 (K, MO); Fenerive, Decary 3907 (P, TAN); Ambila, Decary 6310(K, P), Decary 6397 (P); Zahamena PA, Decary 16798 (P); Mangabe, Decary 16872 (K, P); Mahavelona (Foulepointe), Decary 16969 (P), Decary 16983 (P); Lac Alaotra, Herb. Jard. Bot. Tananarive 4307 (P); Rendrirendry, 17°55′S, 049°13′E, Iambana et al. 137 (P); Maroantsetra, Leeuwenberg 13941 (MO, P, TAN, WAG); Masoala PA, Nicoll et al. 554 (K, MO, P, TAN, WAG); St-Marie, Pervillé 231 (P); environs du confluent de l’Onive et du Mangoro, Perrier dela Bâthie 17150 (P); bord de l’Onive près Antanandavohily-Antalaha, Rakotozafy 517 (TAN); Zahamena PA, Réserves Naturelles 4947-RN (P), Réserves Naturelles 7260-RN (P), Réserves Naturelles 10663-RN (P), Réserves Naturelles 10881-RN (P); Betampona RN, Réserves Naturelles 3954-RN (P, TAN); Fenerive, Réserves Naturelles 7840-RN (P); Sahamalaza, Réserves Naturelles (Laibosaka) 12603-RN (TAN); Androrangabe, Réserves Naturelles (Laibosaka) 12614-RN (TAN); St-Marie, Antongil, Richard comm. 186 (P); Ambahy Forest, ca. 20 km S of Nosy Varika, Rogers 283 (MO, P). Toliara: Prov. Tuléar, Poisson 180 (P); entre le rite de l’hombre et Fort-Dauphin, Rabevohitra 2230 (K, MO, P, TAN).

16. Gouania taolagnarensis Buerki, Phillipson & Callm., sp. nov. TYPE: Madagascar. Toliara: Com. Manambaro, 3 km O de Manambaro, bord de la RN13, 25°01′44″S, 46°46′51″E, 14 m, 23 Mar. 2005 (fl. & imm. fr.), S. Buerki & P. B. Phillipson 68 (holotype, MO!; isotypes, BR!, G!, K!, NY!, P!, TAN!, US!, WAG!). Figure 11.

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Figure 11

Gouania taolagnarensis. —A. Fruiting branch showing immature fruits concentrated mainly in the distal part of the infructescence. —B. Flower showing the lobes of the disc reaching one sixth of the length of the sepals. —C. Fruit showing the two or three transversal veins on the center of each wing. —D. Leaf, adaxial surface. —E. Leaf, abaxial surface, showing the asymmetric limb and the quaternary veins that are particularly well developed on the larger lobe. A–E drawn from Buerki & Phillipson 64 (TAN).

Haec species a congeneris madagascariensibus foliis ovatis usque cordatis ad basem asymmetricis venulis quaternariis praeditis, inflorescentia floribusque indumento pallide fusco obtectis atque fructibus secus inflorescentiam ad partem distalem congestis juventute indumento pallide luteo vestitis deinde rubescentibus quaque ala in centro lineis transversalibus duabus vel tribus notata facile distinguitur.

Woody liana climbing to 10 m; stems dark green, drying brown, densely pubescent with a brown indument; stipules pubescent on the 2 faces with brownish trichomes, (2–)3(–4) × ca. 1 mm, caducous; tendrils pubescent. Leaves ovate to cordate; petioles (8–)10–15 mm, densely pubescent with a brown trichome; leaf blades 4–5(–6) × (2.5–)3–3.5 cm, discolorous; secondary veins alternate, 6 to 7 pairs, reaching and following the margin; tertiary veins apparent, 4 to 7 pairs, arising near the base of the lowest secondary veins and sometimes in the upper part, quaternary veins arising from the first tertiary veins, reticulation scalariform; abaxial surface villous with whitish to pale brown trichomes; midrib, secondary, tertiary, and quaternary veins prominent; adaxial surface sparsely pubescent with pale brown to whitish trichomes; margin sparsely crenulate from the base to the apex; base of the young leaves rounded, cordate and asymmetric on mature leaves; apex generally rounded, sometimes subacute. Inflorescences ± congested, densely pubescent with a pale brownish indument, (6–)10–15(–20) cm, accrescent, the proximal flowers developing before the distal flowers; glomerules generally sessile, basally pedunculate, up to 5-flowered; bracts lanceolate, densely pubescent on both surfaces with a brownish indument, ± persistent, 3(–4) × ca. 1 mm; flowers shortly pedicellate, pedicels up to 1 mm, pubescent with brownish to silver trichomes. Hypanthium obconic, becoming subglobose as the capsule develops; sepals ca. 1.25 × 1 mm, pale yellow, outer surface densely pubescent with silver trichomes, inner glabrous; petals ca. 1 × 0.2 mm, white; stamens totally included in the petal blades, with a white filament and a pale brown, globose anther ca. 0.2 × 0.2 mm; disc flat, ca. 2 mm diam., yellow becoming white with age; lobes ca. 0.2 mm, thicker than the disc, truncate, 1/6 as long as the sepals; stigma with 3 linear lobes, those ca. 0.5 mm, style ca. 1.5 mm. Fruits 0 or developing on each glomerule, spheroid (ca. 1.2 × 1.2 cm), densely pubescent with reddish trichomes, which become brownish after drying, those reaching maturity mainly distributed in the distal part of the infructescence; valves ca. 1.2 × 1.2 cm; immature fruits globose, with a pale yellow indument, with 2 or 3 transverse lines on the center of the wing; seeds pale black, ovoid and slightly flattened on the inner surfaces, ca. 4 × 2.5 × 1 mm.

Distribution and ecology

Gouania taolagnarensis is restricted to southeastern Madagascar in the Taolagnaro region (Fort Dauphin) (Fig. 2C). It grows in evergreen lowland to montane rainforest, sometimes in the transition to xerophytic vegetation and in secondary forest on granite, gneiss rock types, and on lateritic soils at an elevational range from sea level to 1000 m.

IUCN Red List category

With an EOO of about 12,719 km², an AOO of 108 km², and only seven subpopulations, three of which occur within protected areas (Andohahela, Zombitsy), Gouania taolagnarensis is thus assigned a preliminary status of Vulnerable (VU B1ab[ii]+2ab[ii]), according to IUCN Red List criteria IUCN, 2001).

Phenology

The new species has been collected in flower from October to January and in fruit in February and March.

Etymology

The epithet of the new species refers to its endemic locale, in the forests around Taolangaro, Toliara Province.

Discussion

Gouania taolagnarensis can be easily distinguished from other species by its ovate to cordate leaves, the asymmetric base of the blade, the infructespresence of quaternary veins, the pale brown indument that covers the inflorescence and the flowers, immature fruits with a pale yellow indument that reddens with maturity, fruits with two or three transverse lines on the center of the wings, and the fruits concentrated at the distal part of the infructescence.

Gouania taolagnarensis is morphologically most similar to G. pannigera in the length of the lobes of the disc and the size and pubescence of the fruits, but differs in having ovate to cordate leaves, the margin of the apex slightly crenulate, an asymmetric blade, quaternary veins well developed in the asymmetric portion, the inflorescence with a brownish indument, the immature fruits with a yellow indument, those reaching maturity becoming reddish mainly distributed in the distal part of the infructescence. Furthermore, G. taolagnarensis appears to be endemic to the region near Taolagnaro (southeastern Madagascar), whereas G. pannigera is confined to the forests and disturbed areas of central Madagascar.

Paratypes

MADAGASCAR. Toliara: Ambinanibe, 25°02′31″S, 46°55′31″E, S. Buerki & P. B. Phillipson 64 (BR, G, K, MO, NEU, P, TAN, US, WAG); Fort-Dauphin, Vahapinsouran, J. Cloisel 94 (P); Chaine Anosyennes from Fort-Dauphin to Ranamafona, [24°25′S, 46°58′30″E], T. B. Croat 31765 (MO, TAN, WAG); Col de Maningotry, [26°42′S, 46°44′30″E], N. Dumetz 1275 (MO, P, TAN); Andohahela PA, 24°47′S, 46°52′E, J. J. Floret, P. P. Lowry II, A. M. J. Leeuwenberg & R. Rajemsa 1968 (MO, P [2]); bassin de réception de la Mananara, pentes occidentales des montagnes entre Andohahela et l’Elakelaka, [24°45′S, 46°44′E], H. Humbert 13949 (P); Forêt de Manantantely, [24°59′S, 46°55′E], Humbert 20368 (P); Baie des Galions (Ranofotsy), [25°09′S, 46°43′E], Humbert 28976 (P); RN7 at 15 km NE of Sakaraha, [22°56′S, 44°33′E], D. Lorence 2098 (K, MO); Andohahela PA, 24°38′S, 46°46′E, S. T. Malcomber, H. van der Werff, C. Hemingway, M. van Bergen, S. Rapanarivo, P. J. Rakotomalaza, O. Andrianantoanina & B. Randriamampionona 2184 (P, TAN); Manasoa, M. Ramarokoto 2100-RN (P, TAN); Andohahela PA, [24°40′S, 46°48′E], Ramarokoto 5018-RN (P, TAN); Andohahela PA, 24°40′S, 46°48′E, B. Randriamampionona 14 (MO, P, TAN, WAG); Andohahela PA, parcelle 1, 24°40′S, 46°48′E, Randriamampionona 92 (MO, P, TAN, WAG); Fort-Dauphin, W. Rauh 1265 (TAN); Distr. Fort-Dauphin, Réserves Naturelles 8584 (P, TAN); Fort Dauphin, M. Scott-Elliott 2568 (K, P).

17. Gouania zebrifolia Buerki, Phillipson & Callm., sp. nov. TYPE: Madagascar. Antsiranana: Sahafary, 12°34′42″S, 49°27′16″E, 215 m, 22 Feb. 2006 (fl.), C. Birkinshaw, M. Andrianjafy & R. Guittou 1563 (holotype, MO!; isotypes, CNARP!, K!, P!, TAN!). Figure 3B–D.

Haec species a congeneris madagascariensibus foliis membranaceis orbicularibus usque reniformibus abaxialiter indumento tenui albo vestitis, venis tertiariis atris crassis reticulum scalariforme formantibus, margine denticulato quoque dente in caespitem trichomatum brunneolorum desinente atque disci lobis longitudine 1/2 sepalorum partem attingentibus facile distinguitur.

Woody liana climbing to 15 m; stems drying brown, finely pubescent to villous with brownish trichomes; stipules villous with brownish trichomes on the upper surface and glabrous on the inner surface, 3(–4) × ca. 1 mm; tendrils pubescent. Leaves orbicular to reniform; petioles (5–)10(–15) mm, pubescent with brownish trichomes; leaf blades 3.5–4.5(–6) × 3.5(–5) cm, membranous; secondary veins alternate to subalternate, 6 to 7 pairs, reaching and following the margin; conspicuous tertiary veins apparent, arising near the base of the lowest secondary veins, this reticulation scalariform, blackish; abaxial blade surface pubescent with fine white trichomes; midrib, secondary, and tertiary veins prominent; adaxial surface sparsely pubescent with white trichomes; margin denticulate to crenulate, with a tuft of brownish trichomes on every tooth; base rounded to shallowly cordate; apex rounded to acute. Inflorescences ± congested, villous with brownish trichomes, (3–)4–4.5(–5.5) cm, consisting of glomerules subtended by stipulelike bracts; glomerules sessile, 4- to 5(to 8)-flowered; bracts triangular-lanceolate, densely pubescent with villous brownish trichomes on the outer surface, glabrous on the inner, ± persistent, (3–)4.5 × ca. 0.5 mm; flowers shortly pedicellate, pedicels to ca. 1 mm, pubescent with villous whitish indument, apparently protandrous. obconic, Hypanthium broadly becoming subglobose as the capsule develops; sepals ca. 0.8 × 0.5 mm, reddish to brown, outer surface villous, inner glabrous; petals ca. 0.75 × 0.2 mm, brownish; stamens slightly longer than the petal blades, with a pale brown filament and a pale yellow, globose anther ca. 0.2 × 0.2 mm; disc flat, ca. 2 mm diam., dark blue when dry; lobes ca. 0.4 mm, thinner than the disc, emarginate or somewhat truncate, 1/2 as long as the sepals; stigma with 3 linear lobes, those ca. 0.4 mm, style ca. 0.6 mm. Immature fruits globose, villous with brownish trichomes; mature fruit not seen.

Distribution and ecology

Gouania zebrifolia is endemic to northeastern Madagascar and only known from a few localities in Antsiranana: Loky-Manamba-to (Daraina), Sahafary, and Montagne des Français (Fig. 2A). The new species grows in semi-deciduous forest at an elevational range of 50–300 m.

IUCN Red List category

With an EOO of about 631 km², an AOO of 36 km², and only three subpopulations, none of which occur within a protected area, Gouania zebrifolia is assigned a preliminary status of Endangered (EN B1ab[ii] + 2ab[ii]), according to IUCN Red List criteria (IUCN, 2001).

Phenology

This species has been collected in flower and with immature fruits in March.

Etymology

This species is named for the unusual dark patterning of darker stripes on a paleblade background formed by the blackish reticulation of the tertiary veins.

Discussion

Gouania zebrifolia can be recognized Maseasily by its orbicular to reniform, membranous leaves covered by fine white indument on the abaxial surface, which contrasts with the conspicuous blackish scalariform reticulation, with a tuft of brown trichomes on each marginal tooth, and the immature fruits villous with brown trichomes. The taxon shares with G. ambrensis the character of disc lobes that are about one half as long as the sepals.