Nordic Journal of Botany 29: 700
707, 2011 doi: 10.1111/j.1756-1051.2011.01297.x, # 2011 The Authors. Nordic Journal of Botany # 2011 Nordic Society Oikos Subject Editor: Martin Cheek. Accepted 2 September 2011 Craterispermum parvifolium and C. robbrechtianum spp. nov. (Rubiaceae) from west central Africa H. Taedoumg, P. De Block, P. Hamon and B. Sonké H. Taedoumg (taedoumghe@yahoo.fr) and B. Sonké, Plant Systematic and Ecology Lab, Higher Teacher’s Training College, Univ. of Yaoundé I, PO Box 047, Yaoundé, Cameroon. BS also at: Service Evolution Biologique et Ecologie, Univ. Libre de Bruxelles
ULB, 50 Av. F. Roosevelt, CP160/12, BE-1050 Bruxelles, Belgique.
P. De Block, National Botanic Garden of Belgium, Domein van Bouchout, BE-1860 Meise, Belgium.
P. Hamon, UMR DIAPC, Inst. de Recherche pour le Développement, 911 avenue Agropolis, BP 64501, FR-34394 Montpellier CEDEX 5, France. Craterispermum parvifolium and C. robbrechtianum spp. nov. are described from the Lower Guinea Domain. Detailed descriptions and distribution maps are provided for each species, their conservation status is assessed and their taxonomic affinities are discussed. An identification key for the Craterispermum species of the Lower Guinea Domain is given. The genus Craterispermum Benth. is distributed in tropical Africa, Madagascar and the Seychelles (Robbrecht 1988). The species are shrubs or small trees with leaves that are brittle when fresh (they snap/break when folded) and pale yellowish or greenish when dry. The inflorescences are axillary, paired at the nodes, usually compact, with few to many small, heterostylous, white flowers. The ovary is bilocular with a single, apically attached, pendulous ovule in each locule. One ovule aborts and the fleshy fruit contains a single seed shaped like an asymmetrical shallow or deep bowl. The seed has a peculiar, discontinuous seed coat, comprised of isolated cells with ring-like thickenings (Igersheim 1992). Craterispermum species have been shown to accumulate aluminium in leaves and stem tissue (Jansen et al. 2000); the pale yellow or green colour of the dried leaves is typical for aluminium accumulating species. Because of the above-mentioned characters, Craterispermum is easily recognized at the genus level. However, many of the species look similar and identification at the species level is difficult. No recent treatment for the whole genus exists, except in certain local floras (like ‘Flora of tropical east Africa’; Verdcourt 1976). Until now, the numerous specimens collected in Africa and Madagascar over the last two hundred years remain mostly unidentified at species level, partly because the material is often very poor. Flowers are short lived and not often collected; fruits are probably quickly eaten after maturity. Both flowers and fruits fall off easily during drying and pressing because of the compact inflorescences. This also makes new Craterispermum species hard to describe. Next to the 16 species currently known to science (Govaerts et al. 2011), several new species exist, both in continental Africa (Sosef et al. 2006) and in Madagascar (Verdcourt 1973, Randriamboavonjy and De 700 Block 2010). In this paper, we describe two new species from Cameroon, Gabon and Rio Muni, C. parvifolium and C. robbrechtianum. Methods Herbarium material of the following institutions was studied: BR, BRLU, G, MO, P, WAG and YA. All cited specimens have been seen. Descriptive terminology follows Robbrecht (1988) and Anonymous (1962). Phytogeographical terminology follows White (1979), but we simplified his ‘(sub)centres of endemism’ into Domain and Region. Measurements and other given details are based on the study of herbarium specimens, material conserved in alcohol, and data derived from field notes, using a Leica MZ95 stereomicroscope. In the descriptions and key, inflorescence size does not include the corollas, and given colours (except flower colour) are for dried material. Specimens are cited per country, alphabetically by collector. The conservation status was assessed by applying the IUCN red list category criteria (IUCN 2001). Identification key of species present in the Lower Guinea Domain 1 Tertiary and especially quaternary venation obscure; leaf blades coriaceous. . . . . . . . . . . . . . . . . . . . . . . . . . 2
Tertiary and quaternary venation conspicuous; leaf blades coriaceous or papyraceous . . . . . . . . . . . . . 3 2 Inflorescences 2.2
18.0 mm long, very compact, subcapitate or consisting of 2
3 branches 4.5
15.0 mm long; peduncle 0.6
7.0 mm long; leaf blades 6
231.5
8.0 cm; corolla tube ca 4 mm long . . . C. robbrechtianum Taedoumg & Sonké (Cameroon, Gabon)
Inflorescences 25
65 mm long, not very compact, consisting of 2 branches up to 60 mm long; peduncle 7
23 mm long; leaf blades 11
35 6.0
13.5 cm; corolla tube 6
8 mm long . . . . . . . . . C. ledermannii K. Krause (Cameroon, Equatorial Guinea, Gabon) 3 Stems decurrently ridged; stipules with conspicuous needle-like awn; leaf blades 3.0
14.5 cm long; secondary, intersecondary and tertiary nerves parallel and9 perpendicular to midrib . . . . . . . . . . . . . . . . . . . . 4
Stems not decurrently ridged; stipules without needlelike awn; leaf blades 5.5
25.5 cm long; nervation not as above . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 4 Pedicels of fruits 1.0
1.5 mm long, leaf blades papyraceous, 3.3
11.0 0.9
3.5 cm, quaternary venation obscure; stipules persistent; inflorescences with 1
4 flowers; peduncles 5 4.5 mm long. . . . C. parvifolium Taedoumg & Sonké (Cameroun, Equatorial Guinea, Gabon)
Pedicels of fruits 3
5 mm long; leaf blades coriaceous, 5.0
14.51.7
5.3 cm, quaternary venation moderately prominent on both surfaces, closely and irregularly reticulate; stipules caducous and generally only present on the youngest nodes; inflorescences with 3
several flowers; peduncles 4
9 mm long. . . . . . . C. caudatum Hutch. (Senegal to Gabon) 5 Bracts 7
11 mm long, triangular with apex long acuminate; young branches with granular texture; inflorescences subcapitate; peduncles 1
5 mm long . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C. aristatum Wernham (Cameroon, Nigeria)
Bracts ca 1.5 mm long, triangular with apex acute; young branches smooth; inflorescences subcapitate or consisting of 2
3 branches; peduncles 1.4
20.0 mm long. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 6 Inflorescences subcapitate or rarely with two very short branches, very compact; peduncles stout, 1
7 (10) mm long . . . . . . . . . . . . . . .C. schweinfurthii Hiern (Nigeria to Tanzania and Mozambique)
Inflorescences with 2
3 branches each 1.5
20.0 mm long or rarely subcapitate especially in young stage, not compact; peduncles slender, (7
)10
23 mm long . . . . . . . . . . . . . . . . . . . . . . . . . . . .C. cerinanthum Hiern (Ivory Coast to D.R. Congo) Shrub or treelet 1.0
3.5 m tall; all vegetative and generative parts glabrous externally. Stems pale grey; young branches greenish or grayish to brownish, smooth but each internode with two distinct decurrent ridges in line with the stipular awn. Stipules persistent, with sheath 0.9
2.5 mm long, apex with a needle-like awn 2
8 mm long. Leaves petiolate; petioles canaliculate, 2.8
9.0 mm long; leaf blades narrowly obovate or narrowly oblong to obovate, 3.3
11.0 0.9
3.5 cm, papyraceous, green above, paler green below; base cuneate; apex acuminate-caudate, acumen (5
)9
16 mm long; margins somewhat revolute; midrib prominent below; secondary nerves 9
12 pairs, slightly to moderately prominent on both surfaces, secondary, intersecondary and tertiary nerves parallel and9perpendicular to midrib; quaternary venation obscure. Inflorescences supra-axillary, borne 1
2 mm above the nodes, paired and opposite, erect, subcapitate, 1.5
5.51.5
3.0 mm, 1
4-flowered; peduncle flattened, 0.5
4.5 mm long; bracts narrowly triangular, 1
4 mm long; higher order bracts and bracteoles broadly triangular (0.3
)0.6
0.8 0.6
0.8 mm, apex obtuse, margins sometimes sparsely ciliate or bearing sparse colleters near the base. Flowers presumed heterostylous (but only brevistylous morph known), 4-merous, sessile. Brevistylous flowers: Hypanthium greenish white; calyx tube (0.3
)0.5
0.8 mm long; calyx lobes triangular, 0.3
0.6 mm long, apex obtuse, margins sometimes sparsely ciliate or bearing sparse colleters. Corolla white; tube narrowly cylindrical, 3
4 mm long, sparsely to densely pubescent with long erect hairs in the throat and upper quarter of the tube; lobes 2.0
2.5 mm long, sparsely to densely pubescent with long erect hairs in the basal half inside, but hairs absent from the margins, tips acute with a subapical spike-like protuberance. Stamens inserted below the level of the throat, only apices of anthers exserted from corolla tube; anthers 0.7
1.0 mm long, white; filaments 0.3
0.4 mm long. Ovary 0.8
1.0 mm long. Style and stigma included in the corolla tube, ca 3 mm long, glabrous; stigma bilobed, stigmatic lobes ca 0.7 mm long. Fruits spherical, asymmetrical, ca 9 mm in diameter, purple or dark violet when ripe, shortly pedicellate with pedicels 1.0
1.5 mm long. Ethymology The species is named for its small leaves. Habitat and distribution Craterispermum parvifolium Taedoumg & Sonké sp. nov. (Fig. 1) A Craterispermo caudato Hutch. foliis papyraceis, inflorescentiis 1
4-floris et pedicellis fructiferis brevioribus praecipue differt. Type: Cameroon, southwest of Nkoadjap, ca 20 km east of Campo (2820?17.34??N, 9856?41.4??E), 16 May 2009, Lachenaud, Lemaire, Simo and Sonké 795 (holotype: BR, isotypes: BR, MO, P, YA). Grows mostly in humid evergreen forest rich in Caesalpinioideae and in riverine forest. 0
750 m a.s.l. The new species occurs in the Lower Guinea Domain of the Guineo
Congolian Region, restricted to southern Cameroon (north of Bipindi), Equatorial Guinea (Rio Muni) and Gabon. The species is mostly collected from the Kribi-CampoMa’an area in Cameroon (Fig. 2). Phenology Flowers: Feb
Mar, Jun
Oct. Immature fruits: Dec
Feb, Jun
Oct. Mature fruits: May. 701 Figure 1. Craterispermum parvifolium sp. nov. (A) flowering branch, (B) detail of higher order venation, (C) stipule and part of internode, showing decurrent ridge, (D) brevistylous flower from a 1-flowered inflorescence (bracts, bracteoles, calyx, corolla), (E) apex of corolla lobe, (F) immature fruit. (A)
(C) Sonké and Essono 2572 (BR), (D)
(E) Bos 7138 (BR), (F) Bos 5402 (BR). Drawn by Antonio Fernandez. 702 Figure 2. Distribution of Craterispermum parvifolium sp. nov. Critical remarks Flowers and fruits are rare on the specimens of C. parvifolium. Only brevistylous flowers were seen and measurements were based on a single flower from each of three separate specimens. Similar species The affinities of C. parvifolium appear to lie with C. caudatum in sharing decurrently ridged twigs, small, caudate-acuminate leaves and stipules with long needlelike awns. However, C. parvifolium differs from C. caudatum by the following characters: the texture of the leaves (papyraceous in C. parvifolium versus coriaceous in C. caudatum), the nature of the quaternary venation (obscure versus moderately prominent and closely reticulate), the number of flowers per inflorescence (1
4 vs 3 to several) and the length of the pedicels in fruiting stage (pedicels 1.0
1.5 mm long vs 3
5 mm long). Conservation status IUCN red list category: ‘Vulnerable’ (Vu), B1ab (ii, iii); B1
total extent of occurrence (EOO) less than 20 000 km2 (ca 17883.12 km2); a
existing at no more than ten locations; b (ii, iii)
continuing decline inferred. In the Kribi-Campo-Ma’an area, where the species is most often collected, the forest habitat of C. parvifolium is threatened with clearance for agriculture (Taedoumg pers. obs.). Furthermore, the Cameroonian government has started the construction of a deep-water port in the same area, which will certainly result in extensive habitat loss. However, this species is also present in regions in Came- roon that are relatively well conserved, such as the Massif of Ngovayang, as well as in Gabon and Rio Muni. Additional specimens examined (paratypes) Cameroon: Just east of Kribi, riverine forest of tributary to Kienke river, 25 Sep 1969, Bos 5402 (BR, MO, WAG, YA); Riverine forest of tributary to Kienke river, just east of Kribi, 26 Jan 1970, Bos 6161 (BR, MO, WAG, YA); 15 km from Kribi, 1 km south of Ebolowa road, high forest exploitation, Rouillon, 20 Feb 1970, Bos 6388 (BR, WAG, YA); Km 36 Kribi-Campo, 24 Jul 1970, Bos 7138 (BR, WAG, YA); Bifa, piste sur la route Kribi-Ebolowa, à 5 km au southeast de Zingui, 14 Apr 2007, Droissart and Simo 372 (BRLU, YA); southwest de Nko’Adjap, ca 20 km east Campo, 16 May 2009, Lachenaud, Lemaire, Simo and Sonké 802 (BR, YA); Abords de la Lobe, 25 km eastnortheast of Campo, 23 Mar 1968, Letouzey 9126 (BR, P, YA); Bifa, 18 Oct 2008, Sonké and Simo 5154 (BR, BRLU, MO, P, WAG, YA); Campo Ma’an area, Bibabimvoto, forest around Bongola river, 31 Jan 2000, Tchouto, Elad, Balogue and Mamia 2502 (WAG); Campo Ma’an area, Bibabimvoto, on Dipikar Island along transect T2, 19 Jul 2000, Tchouto, Elad and Nnanga T2X156 (WAG); Campo Ma’an area, Mvini, in the National Park, along transect T5, 13 Jun 2000, Tchouto, Elad and Nnanga T5X78 (WAG); Campo Ma’an area, Mvini, in the National Park, along transect T6, 16 Sep 2000, Tchouto, Elad and Nnanga T6X113 (WAG); Campo Ma’an area, road Nko elon-Mvini, trail to Mesok mesok creek, 14 Jun 2001, Tinde van Andel, Maas and Mva 3682 (WAG); Mimfia, Dec 1913, Zenker 509 (BR, G, MO, WAG); Bipindi ‘Bipinde’, 1913, Zenker 703 4829 (BR, MO); Bipindi ‘Bipinde’, 1913, Zenker 4931 (BR, MO).
Equatorial Guinea (Rio Muni): Ayee, Sofogo, 12 Sep 2001, Essono and Ndong 323 (BRLU); SW du Parc National de Monte Alén, 2 km northeast du site de traversée du rio Uolo pour aller aux cataractas, 25 Jun 2002, Senterre and Nguema 3021 (BRLU); Essamba, 16 Aug 2001, Sonké and Essono 2572 (BR, BRLU, YA).
Gabon: Monts de Cristal, SEEF logging Concession, 23 Oct 2010, Stévart, Niangadouma, Akouangou and Kaparidi 3600 (BRLU, MO). with short erect hairs over the entire length inside, tips acute with a subapical spike-like protuberance. Stamens with anthers completely included in corolla tube or only anther apices exserted, inserted below the level of the throat; anthers 1.0
1.5 mm long; filaments ca 0.2 mm long. Ovary ca 1 mm long. Style and stigma exserted, ca 5.5 mm long; stigma bilobed, stigmatic lobes ca 1 mm long. Fruits urceolate to subglobose, usually wider at the base than at the tip, asymmetrical, 1.5
1.7 cm diam. at maturity, immature fruits usually ovoid in shape, successively green, whitish and violet at maturity, sessile to very shortly pedicellate, pedicels up to 2.5 mm. Craterispermum robbrechtianum Taedoumg & Sonké sp. nov. (Fig. 3) Ethymology A Craterispermo ledermannii K. Krause inflorescentiis minus robustis compactioribusque, pedunculis brevioribus (1
7 mm longis) et corollis tubis brevioribus praecipue differt. The species is named after Prof. Dr Elmar Robbrecht, Rubiaceae specialist and former Head of the Dept of Phanerogamy in the National Botanical Garden of Belgium for his work on African Rubiaceae. Type: Cameroon, 30 km from Kribi-Ebolowa road (02849?N, 10807?E), 4 Feb 1970, Bos 6235 (holotype: WAG, isotypes: BR, WAG). Habitat and distribution Shrub or treelet up to 4(
6) m tall; all vegetative and generative parts glabrous externally. Young branches greenish or brownish, often somewhat granular in outlook. Stipules persistent, with sheath 1.5
4.0 mm long, subtruncate or with very short awn (B1 mm long), keeled. Leaves petiolate; petioles canaliculate, 3
35 mm long; leaf blades narrowly elliptic or narrowly obovate, more rarely elliptic or obovate, 6
23 1.5
8.0 cm, coriaceous, greenish or brownish above, paler green or brown or fawnish below; base cuneate, apex acuminate, acumen 7
20 mm long; margins revolute; midrib prominent below; secondary nerves 7
11 pairs, moderately prominent on both surfaces, tertiary venation moderately prominent on upper surface, obscure on lower surface; secondary and higher venation obscure in fresh condition. Inflorescences supra-axillary, borne 2
9 mm above the nodes, paired and opposite, erect, 2.2
18.0 3
22 mm, very compact, with several to numerous flowers, subcapitate or consisting of 2
3 branches each 4.5
15.0 mm long; peduncle subcylindrical to flattened, (0.6
)2
8 mm long; bracts broadly triangular, keeled, 1.0
1.5 mm long, apex acute to very shortly acuminate; bracteoles broadly triangular, 0.5
1.0 mm long, apex truncate to obtuse. Flowers heterostylous, 5-merous, sessile; hypanthium pale green or whitish; corolla white; anthers and filaments white; style and stigma glabrous. Brevistylous flowers: Calyx tube ca 0.4 mm long, subtruncate or with short teeth ca 0.2 mm long. Corolla tube ca 4 mm long, pubescent in throat and upper half inside; lobes ca 2 mm long, with short hairs at the base inside, tips acute with a subapical spike-like protuberance. Stamens with anthers completely exserted, inserted at the level of the throat; anthers 1.0
1.5 mm long; filaments ca 1 mm long. Ovary ca 1 mm long. Style and stigma included in corolla tube, ca 3.3 mm long; stigma bilobed, stigmatics lobes ca 1 mm long. Longistylous flowers: Calyx tube ca 0.5 mm long, subtruncate or with short teeth 0.2
0.3 mm long. Corolla tube ca 4 mm long, pubescent at throat and upper 1/3th of corolla tube inside; lobes ca 4 mm long, densely pubescent 704 The new species grows in old secondary, primary and riverine forest. 10
500 m a.s.l. It occurs in the Lower Guinea Domain of the Guineo
Congolian Region, restricted to southern Cameroon and Gabon. The species is mostly collected from the Kribi-Edéa area in Cameroon (Fig. 4). Phenology Flowers: Oct
Feb, Apr
Jun. Immature fruits: Oct
Apr, Jul. Mature fruits: Mar
Apr. Critical remarks 1) Only few flowers were available for measurement, 2) Zenker 426 from G and WAG is a mix of two closely related species occurring in the same area in Cameroon. The other species remains undescribed (due to a paucity of material) and differs from C. robbrechtianum in having caducous stipules with needle-like awns and more densely reticulate leaves. Similar species As stated in the diagnosis, Craterispermum robbrechtianum is closely related to C. ledermannii by the coriaceous leaf blades with obscure to invisible tertiary venation (in fresh condition), the keeled stipules with very short awn and the many-flowered inflorescences consisting of 2 or 3 very congested branches. However, the two species can easily be distinguished by flower and inflorescence characters. Craterispermum ledermanni has longer peduncles, less compact but more robust inflorescences, larger bracts and bracteoles and longer flowers. Conservation status IUCN red list category: ‘Least Concern’ (LC). Total extent of occurrence (EOO): 114 404.49 km2. This species is known from 11 locations and 56 specimens are recorded. It is widely distributed and the gaps observed in its distribution (in Rio Muni and Eastern Gabon) are the result of poor collecting rather than a fragmented habitat. We judge that no imminent threat weighs on this species. Figure 3. Craterispermum robbrechtianum sp. nov. (A) flowering branch, (B) stipule, (C) inflorescence shape (subcapitate, 2- and 3-branched cymes), (D) brevistylous flower (calyx, corolla, anthers), (E) longistylous flower (calyx, corolla, style and stigma), (F) apex of corolla lobe, (G) infructescence with young fruits, (H) young fruit. (A)
(C) Bos 6235 (BR), (D), (F) Bos 6258 (BR), (E) Dibata 24 (MO), (G), (H) Taedoumg and Gonmadje 200 (BR). Drawn by Antonio Fernandez. 705 Figure 4. Distribution of Craterispermum robbrechtianum sp. nov. Additional specimens examined (paratypes) Cameroon: About 12 km from Kribi, Lolodorf road, next to stream in forest, 13 Jan 1969, Bos 3624 (WAG, YA); About 19 km from Kribi, ca 5 km north of Lolodorf road, 18 Feb 1969, Bos 3901 (BR, MO, WAG); 15 km north of Kribi, riverine forest of Mpolongwe, 24 Nov 1969, Bos 5691 (BR, WAG, YA); 30 km from Kribi, Ebolowa road, relict riverine forest, 6 Feb 1970, Bos 6235 (BR, WAG); 40 km north of Kribi, 5 km east of Edéa road, forest track Fifinda Bell, Nov 1970, Bos 6258 (BR, MO, WAG); Several km east of km 40 Kribi-Edéa, Fifinda, 6 Apr 1970, Bos 6727 (BR, WAG, YA); 20 km south of de Kribi, 7 Feb 1983, De Namur 2158 (YA); ca 50 km northwest of Eséka, W of Yaoundé, 16 Dec 1963, De Wilde J. J. F. E. 1490B (BR, WAG); ca 50 km northwest of Eséka, W of Yaoundé, Kelé-river, 22 Nov 1963, De Wilde W. and De WildeDuyfjes B. 1291 (BR, WAG); ca 30 km westnorthwest of Eséka, west of Yaoundé, along small river, 15 Dec 1963, De Wilde W. and De Wilde-Duyfjes B. 1490 (WAG); Campo Ma’an area, Bongola, along Bongola river, 29 Jan 2000, Elad, Tchouto, Nganwui and Ondoua 1220 (WAG); southeast of Nko’Adjap, ca 20 km east of Campo, 15 May 2009, Lachenaud, Lemaire, Simo and Sonké 772 (BR, YA); Nko’Adjap, ca 20 km east of Campo, 15 May 2009, Lachenaud, Lemaire, Simo and Sonké 777 (BR, YA); southwest of de Nko’Adjap, ca 20 km east of Campo, 16 May 2009, Lachenaud, Lemaire, Simo and Sonké 804 (BR, YA); southeast of Elogbatindi, route de Bipindi, 18 May 2009, Lachenaud, Lemaire, Simo and Sonké 832 (BR); 14 km southeast of Elogbatindi, route de Bipindi, 18 May 2009, Lachenaud, Lemaire, Simo and Sonké 841 (BR, YA); 4 km east of km 58 of road Edéa-Kribi, north of 706 road to Mboké, 3 May 1965, Leeuwenberg 5708 (WAG); Mvini, 35 km east of Campo, 1 Oct 1983, Mikio Kaji 83 (YA); Mémel II, 1 Mar 2004, Sonké 3245 (BR, BRLU, MO); Mvilé, 3 km westnorthwest of Ngovayang, 28 Nov 2005, Sonké and Djuikouo 4149 (BR, MO, YA); Mvilé, 3 km northnorthwest of Ngovayang, 30 Nov 2005, Sonké and Djuikouo 4178 (BR, BRLU, MO, WAG, YA); Mvilé, 3 km northnorthwest of Ngovayang, 1 Dec 2005, Sonké and Djuikouo 4222 (BR, MO, YA); 2 km northwest of Mbikiliki, 18 Jan 2006, Sonké and Djuikouo 4259 (BR, MO, YA); 2 km northwest of Mbikiliki, 19 Jan 2006, Sonké and Djuikouo 4282 (BR, YA); 2 km northwest of Mbikiliki, 19 Jan 2006, Sonké and Djuikouo 4288 (BR, MO, YA); 3 km northwest of Mbikiliki, 21 Jan 2006, Sonké and Djuikouo 4335 (MO, YA); Bibondi, 21 Jan 2005, Sonké and Nguembou 3712 (BR, BRLU, MO, WAG, YA); Bibondi, 23 Jan 2005, Sonké and Nguembou 3774 (BR, BRLU, MO, WAG, YA); Bibondi, 24 Jan 2005, Sonké and Nguembou 3780 (BR, BRLU, MO, WAG, YA); 5 km west of Ngoyang, 16 Sep 2005, Sonké and Nguembou 3945 (BR, BRLU, MO, WAG, YA); Song Bikin, 5 km north of Bipindi, 14 Jan 2005, Sonké, Nguembou and Esono 3626 (BR, MO, YA); Bifa, 15 Oct 2008, Sonké and Simo 5104 (BR, BRLU, MO, WAG, YA); Bifa, 16 Oct 2008, Sonké and Simo 5114 (BR, BRLU, MO, WAG, YA); Bifa, 18 Oct 2008, Sonké and Simo 5141 (BR, BRLU, MO, WAG, YA); Bifa, 18 Oct 2008, Sonké and Simo 5150 (BR, BRLU, MO, YA); Bifa, 18 Oct 2008, Sonké and Simo 5156 (BR, BRLU, MO, YA); Bifa, 19 Oct 2008, Sonké and Simo 5162 (BR, BRLU, MO, YA); Lac Tissongo, 2 Feb 2009; Sonké, Taedoumg and Simo 5243 (BR, MO, P, YA, WAG); Mbikiliki, 20 Jan 2008; Taedoumg and Gonmadje 200 (BR, YA); Mbikiliki, 20 Jan 2008, Taedoumg and Gonmadje 211 (BR, YA); Campo Ma’an area, Bibabimvoto, on Dipikar island along transect T2, 19 Jul 2000, Tchouto, Elad and Nnanga T2X271 (WAG); Lake Tissongo, 24 Jun 1986, Thomas 6169 (MO, YA); Mimfia, Oct 1913, Zenker 426 (BR, G pro parte, MO, WAG pro parte); Bipindi ‘Bipinde’, 1904, Zenker 2807 (BR, G). Gabon: ca 20
30 km northnorthwest of Ndjolé, 1 Oct 1994, Breteler 13112 (WAG); CFAD de Rimbuman Hijau au SO du Parc National de la Lopé, 29 Jan 2009, Dauby, Nguema, Mounoumoulossi and Bissiemou GD 1475 (BRLU); E du Parc National de Waka, ca 5 km au S de la rivière Mayi, 29 Feb 2009, Dauby, Nguema, Mounoumoulossi and Bissiemou GD 649 (BRLU); 19 km eastnortheast of Bellevue, 7 Jan 1987, Dibata 24 (MO, WAG); Abanga, chantier C. E. T. A., 3 Jun 1963, Hallé 2201 (P); 8 km southsouthwest of Makokou, near Ivindo river, right bank, 9 Nov 1977, Leeuwenberg 11484 (BR, WAG); Forest near Bellevue, 3 Jun 1987, Thomas 6646 (BR, WAG); Near Lastoursville, Chantiers SBL, 19 Nov 1988, Van der Maesen, Louis and De Bruijn 5645 (WAG); 31 km eastnortheast of Lambaréné, 11 km east of Bellevue, 7 Apr 1994, Wieringa and Haegens 2677 (WAG). Acknowledgements
We want to express our thanks to the Belgian National Focal Point for the Global Taxonomy Initiative and to the National Botanical Garden of Belgium for financial and logistic support offered to the first author during his stays in Belgium where this study was undertaken. Fieldwork in Cameroon was supported by the National Geographic Society through its Committee for Research and Exploration (grant no. 7711-04) and ‘Sud Expert Plantes
projet no. 375’ (project under the French Ministry of Foreign Affairs). We thank the herbarium curators of BRLU, G, MO, P, WAG and YA for the loan of plant material. We thank Daniel Geerinck for translating the Latin diagnoses. Antonio Fernandez is gratefully acknowledged for making the line drawings. Marie-Noël Djuikouo, Vincent Droissart, Christelle Gonmadje, Charlemagne Nguembou and Murielle Simo are thanked for help with the collection of plant material during fieldwork in Cameroon. We are grateful to Steven Dessein for his help with the IUCN assessments. References Anonymous 1962. Systematics Association Committee for descriptive biological terminology. II. Terminology of simple symmetrical plane shapes (chart 1).
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Bhttp://www.kew.org/wcsp/rubiaceae/, accessed Apr 2011. Igersheim, A. 1992. The ovary, fruit and seed development of Craterispermum.
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