Vera-Duthiea, Speta

29. Vera-duthiea Speta View in CoL View at ENA

in Phyton (Horn, Austria) 56(2): 154 (2016).

Typus generis:— V. senegalensis (Kunth) Speta View in CoL (holotype).

≡ Duthiea Speta View in CoL in Stapfia 75: 170 (2001) [repl. syn.], nom. illeg., non Duthiea Hack. View in CoL in Verh. Zool.-Bot. Ges. Wien 45: 200 (1896) [ Poaceae View in CoL ], nec Duthiea Manza View in CoL in Proc. Natl. Acad. U.S.A. 23: 48 (1937), nom. illeg. [ Corallinaceae View in CoL , Rhodophyta] ( Figs 72–73 View FIGURE 72 View FIGURE 73 ). Typus generis:— D. senegalensis (Kunth) Speta View in CoL (holotype).

Description:—Medium sized bulbous geophyte. Bulb hypogeal, ovoid to subglobose, 3‒6 cm in diam., with white, fleshy, compact inner scales and membranose outer tunics. Roots thickened and branched. Leaves 2‒10 per bulb, hysteranthous or synanthous, 6‒30 cm long, narrowly linear to lanceolate, subterete to plane or canaliculated, green, somewhat glaucous, smooth, glabrous, commonly with darker maculations along basal portions, sometimes giving a zebra banding pattern. Inflorescence a lax, erect raceme, 3‒35 cm long, with 3–30 flowers; peduncle 12‒60 cm long, erect to leaning, terete, smooth, sometimes slightly mottled at base; pedicels 3‒40 mm long, subpatent proximally and arching downwards distally at anthesis, erect in fruit. Bracts deltoid, short, 2‒5 mm long, lowermost with short spur, caducous and leaving distinct scar; bracteoles absent. Flowers stellate with strongly reflexed tepals at full anthesis, nodding, nocturnal, opening in late evening and closing before sunrise, fragrant during night. Tepals 6, biseriate, 10‒15 mm long, narrowly oblong to lanceolate, yellow, brown, carneous or whitish with darker brownish-greenish longitudinal band more evident on abaxial side, almost free to shortly connate for 1‒2 mm. Stamens 6, erect, sigmoid, yellow, brown to white or cream colour; filaments 8‒12 mm long, linear and subterete, narrowed below and incurved approaching ovary, connivent to style along middle, and spreading distally, very shortly adnate to tepals at base; anthers oblong, 2‒3 mm long, subbasifixed, yellow, orange or green, with yellow or white pollen. Ovary ovoid to conical, 3‒5 mm long, greenish. Style 6‒8 mm long, erect or deflexed to approach stamens spreading distally, white, columnar, with small stigma. Capsule ovate, oblong or ellipsoid, trigonous, deeply 3-lobed with sharp angles, 9‒20 mm long, pale brown, valves completely dehiscing from base, tepals cohering and inrolled above ovary after anthesis, circumcissile from base and persisting as a cap at the top of the developing capsules. Seeds ellipsoidal to broadly ellipsoid, flattened, 6‒10 mm long, testa black, glossy, with sinuous anticlinal cell walls.

Number of species and distribution:— Vera-duthiea includes 6 species occurring mainly in Southern and Central Africa, and extending north to the Arabian Peninsula in the Dhofar Mountains in Oman and southern Yemen ( Patzelt et al. 2021). It is therefore restricted to the Uzambara‐Zululand, Karoo‐Namib and Guineo‐Congolian Regions, and the Zambezian, Erithraeo‐Arabian, Omano‐Sindian and Sahelo‐Sudanian Subregions (sensu Takhtajan 1986 and Martínez-Azorín et al. 2023a) ( Fig. 71 View FIGURE 71 ). The study of herbarium material of this genus deposited at P, and other herbaria from most countries in Central Africa, showed a large variability in morphology regarding size and morphology of bulbs, leaves, and flowers. Therefore, further studies based on fresh material are urgently needed to ascertain the real diversity of this genus. For further information on Vera-duthiea species see Martínez-Azorín et al. (2018b, 2019a), Manning & Goldblatt (2018), Crouch et al. (2020), and Patzelt et al. (2021).

Karyology:—Apparently not studied yet ( Goldblatt et al. 2012).

History, diagnostic characters, and taxonomic relationships:—The morphological and genetic studies by Pfosser & Speta (2001) led Speta (2001) to describe Duthiea to include three species from Central to northwestern Africa: D. senegalensis ( Kunth 1843: 334) Speta (2001: 170) , the type of the genus, D. macrocarpa (Stedje 1987: 664) Speta (2001: 170) , and D. noctiflora ( Battandier & Trabut 1894: 505) Speta (2001: 170) . This genus was characterised by the imbricate bulb scales, proteranthous leaves, patent pedicels, perigone slightly connate at the base, nocturnal flowers, white and thin filaments, style broadened at apex, ovoid ovary, and flattened and black seeds ( Speta 2001). However, Duthiea Speta is illegitimate due to the later homonym of both the previous Duthiea Hackel (1896: 200) (Poaceae) and Duthiea Manza (1937: 48) , nom. illeg. ( Corallinaceae ). To solve this, Speta (2016) published Vera-duthiea as a “nomen novum” for his illegitimate Duthiea and transferred to his new genus the three above cited species. Martínez-Azorín et al. (2018b) described V. zebrina Mart. -Azorín et al. (2018b: 285) representing the extension of the distribution range of this genus to eastern Southern Africa. Manning & Goldblatt (2018) described Drimia vespertina for plants occurring in Kaokoland in northwestern Namibia and Martínez-Azorín et al. (2019a) effected five further new combinations in Vera-duthiea including V. vespertina and other taxa described from Namibia and Senegal. Patzelt et al. (2021) described V. capillifolia Patzelt et al. (2021: 46) from Oman, being the first record of the genus outside of Africa. Drimia vespertina is provisionally placed in Thuranthos , as discused above, based on its basally expanded filaments.

The phylogenetic results of Martínez-Azorín et al. (2023a) include seven samples of Vera-duthiea from South Africa, Senegal, and Oman, which form a strongly supported clade, confirming the phylogenetic results of Pfosser & Speta (2001, 2004). Vera-duthiea is sister to Ebertia from Guinea and the clade combining both these genera is related to Iosanthus , Indurgia , Urginea , and Spirophyllos . Our results agree with those of Pfosser et al. (2006), whose samples of Urginea noctiflora resolved sister to Urginea s.str., and therefore are not included in Vera-duthiea . While describing his new genus, Speta (2001) also included Urginea noctiflora based on the nodding, nocturnal flowers. This species, however, is separated here into the new monotypic genus Spirophyllos . The exclusion of U. noctiflora from Vera-duthiea is also supported by the lack of the maculate leaves typical of that genus, the straight filaments that are connivent to the style and cross each along the upper third, and by its distinctly coiled leaves, unique in Urgineoideae .

Here we accept Vera-duthiea as a genus occurring in Southern and Central Africa extending to the Arabian Peninsula, characterised by the hypogeal, compact bulb scales; leaves usually maculate, at least at base; lax racemes; the absence of bracteoles; nodding, nocturnal flowers; free to shortly connate, reflexed tepals; filaments narrow and constricted at the joint to the tepals that are shortly adnate, incurved along the lower half, almost connivent to style in middle section and spreading distally; anthers near basifixed; style suberect to distinctly deflexed at full anthesis; subcapitate stigma; and the flattened, subelliptic seed with prominent central embryo. Other genera with superficially similar flowers are Indurgia , Thuranthos , and Zingela , with which it might be confused. However, Thuranthos shows bulbs with very loose scales; bracteoles present and distinct, and filaments expanded along the basal half. The members of Indurgia are restricted in range to southwestern Asia, and also differ by their unspotted leaves; straight, erect to suberect filaments; erect, usually thickened, subclavate style; truncate, trigonous stigma; apiculate capsule valves; and seeds disposed vertically in one or two rows per locule ( Yadav et al. 2019). To date, Zingela remains a monotypic genus differing in the very loose, cucullate, bulb scales; prominently keeled leaves; the presence of distinct bracteoles; the diurnal flowers; the spreading filiform filaments; the coiled dehisced anthers; the erect style; and the truncate capsule valves ( Crouch et al. 2018, 2020).

The circumscription of Vera-duthiea accepted in the present work differs from Martínez-Azorín et al. (2023a) based on our recent phylogenetic studies on Drimia macrocarpa , as discussed above in the genus Thuranthos . We were unable to study fresh material of the type species of Vera-duthiea , though the published phylogenetic evidence ( Martínez-Azorín et al. 2023a) and the study of several herbarium collections from Senegal and Central Africa deposited at Herb. P agree with the genus flower morphology (basally narrowed filaments) accepted in this work.

Accepted species:—

Vera-duthiea capillifolia A.Patzelt, M.Pinter & Mart. - Azorín in Phytotaxa 524: 46 (2021) ( Figs 6.2 View FIGURE 6 , 73.1 View FIGURE 73 ). Type:— OMAN. Jabal Qamar, Wadi Kharfut, elev. 22 m, 13 February 2012, A. Patzelt, D. Lupton, L. Al Harthy, I. Al Rashdi & A. Al Hinai AP 4963 (OBG! holo.).

Vera-duthiea reflexa (K.Krause & Dinter) Mart. View in CoL - Azorín, M.B. Crespo, M. Pinter & Wetschnig in Phytotaxa 397(4): 296 (2019) ≡ Albuca reflexa K.Krause & Dinter View in CoL in Bot. Jahrb. Syst. 51(3–4): 445 (1914), basionym. Type:— NAMIBIA. Tsumeb (1917): Nord-Hereroland, bei Tsumeb, (–BA), Dinter 2694 (SAM0073723! [2 cross referenced sheets, Art. 8.2 Ex. 4 of the ICN] lecto. designated by Manning & Goldblatt 2018, or perhaps holo.).

Vera-duthiea salmonea (Berhaut) Mart. View in CoL - Azorín, M.B. Crespo, M. Pinter & Wetschnig in Phytotaxa 397(4): 296 (2019) ≡ Urginea salmonea Berhaut, Fl. View in CoL Senegal ed. 2, 428 (1967), basionym. Type:— SENEGAL. Mbao, 15 June 1954, Berhaut 1682 (P00349754! lecto. designated by Martínez-Azorín et al. 2019a: 296; P00349756! isolecto.; P00349752!, P00349753!, P00349755! syn.).

Vera-duthiea sebirii (Berhaut) Mart. View in CoL - Azorín, M.B. Crespo, M. Pinter & Wetschnig in Phytotaxa 397(4): 296 (2019) ≡ Urginea sebirii Berhaut View in CoL in Bull. Soc. Bot. France Mém. 1953−1954: 7 (1954), basionym ( Fig. 6.4 View FIGURE 6 ). Type:— SENEGAL. In “savane boisée” Ngasobil, June–July 1951, Berhaut 461 (P00349746! lecto., perhaps holo., designated by Martínez-Azorín et al. 2019a: 296).

Vera-duthiea senegalensis (Kunth) Speta View in CoL in Phyton (Horn, Austria) 56(2): 155 (2016) ≡ Urginea senegalensis Kunth, Enum. Pl. View in CoL 4: 334 (1843), basionym ≡ Duthiea senegalensis (Kunth) Speta in Stapfia 75: 170 (2001) ≡ Drimia senegalensis (Kunth) J.C.Manning & Goldblatt View in CoL in Edinburgh J. Bot. 60(3): 557 (2004). Type:— SENEGAL. Senegambia, prope Richard-Tol [sic, Richard Toll], Lelievre [not extant at B, probably destroyed during World War II, R. Vogt pers. comm.].

Vera-duthiea zebrina Mart. - Azorín, N.R.Crouch & M.B. Crespo in Phytotaxa 375(4): 285 (2018) ≡ Drimia zebrina (Mart. - Azorín, N.R.Crouch & M.B.Crespo) J.C.Manning & Goldblatt in Bothalia 49(1): 5 (2019) ( Figs 72 View FIGURE 72 , 73.2 View FIGURE 73 ). Type:— SOUTH AFRICA. KwaZulu-Natal. Bela Vista (2632): Ndumo [Ndumu] Hill , Ndumo [Ndumu] Game Reserve , (–CD), 4 November 1968, E.S. Pooley 127 (NU43530! holo.; NH66607! iso.).

= Urginea zebrina Oberm. , in sched.