Urginavia Speta
- Dataset
- A generic monograph of the Hyacinthaceae subfamily Urgineoideae
- Rank
- GENUS
Classification
- kingdom
- Plantae
- phylum
- Tracheophyta
- class
- Liliopsida
- order
- Asparagales
- family
- Asparagaceae
- genus
- Urginavia
description
Description: — Usually tall bulbous geophyte. Bulb hypogeal, rarely epigeal, ovoid to globose, up to 20 cm in diam., scales somewhat loose, heterogeneous in length and vertically imbricate, yellowish and leathery when dry and showing distinct white threads when broken, rarely showing fibrose neck above ground. Roots thickened and branched. Leaves (2 –) 4 ‒ 16 per bulb, narrowly lanceolate to oblong, hysteranthous or rarely partially synanthous, 8 ‒ 60 cm long, plane or channelled, sometimes keeled abaxially along lower portions, margin entire, green or somewhat glaucous, smooth, glabrous, producing white threads when broken. Inflorescence a long, erect, usually multiflowered raceme, with 15 ‒ 700 flowers, (3 –) 10 ‒ 120 cm long; peduncle (6 –) 10 ‒ 100 cm long, terete, erect, smooth and glabrous; pedicels 2 ‒ 30 mm long, subpatent or spreading. Bracts narrowly lanceolate, 2 ‒ 15 mm long, usually caducous or sometimes persisting, lowermost with spur from short to 20 mm long; bracteoles present and distinct. Flowers stellate or with reflexed tepals, erect-patent, diurnal, lasting one or more days. Tepals 6, biseriate, 3.5 ‒ 12.0 mm long, mostly subfree or rarely distinctly connate for 2 ‒ 3 mm at base, lanceolate-ovate to oblong, white, cream, brown or yellow, with darker longitudinal band. Stamens 6, suberect to spreading; filaments 2 ‒ 10 mm long, smooth, usually white and lanceolate to narrowly triangular, flattened or rarely filiform; anthers dorsifixed. Ovary ovate-oblong, 2 ‒ 5 mm long, green to yellow. Style 2 ‒ 9 mm long, erect, white with trigonous undifferentiated or capitate stigma. Capsule obovoid, ellipsoid or subglobose, 4 ‒ 15 mm long, emarginate, valves completely dehiscing from base, tepals remaining below developing capsules. Seeds elliptic or ovate-oblong, 4 ‒ 9 mm long, flattened, with prominent embryo and flat peripheral wings, testa black, with strongly sinuous anticlinal cell walls.
description
Karyology: — 2 n = 20 (De Wet 1957, Jones & Smith 1967, as Urginea altissima Baker; Stedje & Nordal 1987; De Wet 1957, as Urginea multisetosa Baker; Stedje & Nordal 1987, as D. exigua Stedje); 2 n = 22 (Oyewole 1975, as U. altissima; Oyewole 1975, as Urginea gigantea (Jacq.) Oyewole; Oyewole 1975, as Urginea viridula Baker); 2 n = 32 (De Wet 1957, as U. epigea R. A. Dyer); 2 n = 60 (Goldblatt et al. 2012, as D. capensis (Burm. f.) Wijnands).
discussion
History, diagnostic characters, and taxonomic relationships: — Speta (1998 b) described Urginavia to include plants with large bulbs; inflorescence commonly large, long racemose, multi-flowered; spurred bracts and distinct bracteoles; patent pedicels and stellate flowers; tepals only slightly connate at base; nocturnal flowers (sensu Speta 1998 b; doubtful); and flattened black seeds. The new genus was based on morphological and phylogenetic studies (Pfosser & Speta 1999, 2001, 2004) and Speta (1998 b) included in it Urginavia altissima (Linnaeus f. 1782: pl. 199) Speta (1998 b: 87), U. brachystachys (Baker 1892: 474) Speta (1998 b: 87), U. porphyrantha (Bullock 1932: 505) Speta (1998 b: 87), U. micrantha (Richter 1850: 328) Speta (1998 b: 87) (the type), and U. viridula (Baker 1898: 538) Speta (1998 b: 87). Later Speta (2001) added the combination Urginavia epigea (Dyer 1947: t. 1027) Speta (2001: 168). This genus includes a distinct group of relatively large species occurring in Africa, south of the Sahara Desert (Speta 1998 a). However, we transfer Urginea brachystachys to Sekanama, based on the red bulb and translucent withered tepals, among other characters, as discussed above. Manning & Goldblatt (2018) accepted this group of species as D. sect. Urginavia (Speta 1998 b: 86) Manning & Goldblatt (2018: 13) mostly following Speta’s (1998 b) concept, but adding important characters such as welldeveloped bracteoles, diurnal flowers, and tepals persisting below the developing capsule, not cohering into a cap above. Their section included three species for Southern Africa: Drimia altissima (Linnaeus f. 1782: pl. 199) Ker Gawler (1808: t. 1074), D. capensis (Burman 1768: 10) Wijnands (1983: 130), and D. kniphofioides (Baker 1897: 469) Manning & Goldblatt (2003: 111). Manning & Goldblatt (2018) placed Urginea multisetosa Baker (1897: 468) and U. echinostachya Baker (1897: 468) (= Ornithogalum cooperi Baker 1873 b: 284) in their polyphyletic D. sect. Ledebouriopsis, and described the absence of bracteoles in both species. Our phylogenetic results have confirmed that these two species belong to Urginavia, further sharing the diagnostic characters of that genus, which include having distinct bracteoles, evident in the type collections. The phylogenetic analyses of Martínez-Azorín et al. (2023 a) include thirteen samples of Urginavia from Central and Southern Africa and form a perfectly supported clade recognised at the rank of genus. This distinction is morphologically substantiated by their bulb scales that are somewhat loose, heterogeneous in length and vertically imbricate, usually yellowish and leathery when dry, and showing distinct white silky threads when broken (Fig. 65.2), an apomorphy of the genus. Urginavia is sister to a clade including samples of Ledurgia, Thuranthos, and Zingela, which mostly co-occur in distribution, but show very different morphology. Pfosser & Speta (1999, 2001) included a sample of Urginavia micrantha (Richter 1850: 328) Speta (1998 b: 87), the type of the genus, in their phylogenetic analyses involving only the trnL-F region. We were unable to obtain further sequences of other DNA regions for that same sample and accordingly excluded it from our broader analyses. However, the inclusion of the published sample of U. micrantha in our trnL-F matrix confirmed its placement in Urginavia. The taxonomy of the genus requires further resolution assisted by fieldwork across its extensive sub-Saharan range.
distribution
Number of species and distribution: — Urginavia includes 16 species from Southern, East and West Africa, and is restricted to the Cape, Karoo-Namib, Uzambara-Zululand and Guineo-Congolian Regions, and the Zambezian, Erithreo-Arabian and Sahelo-Sudanian Subregions (sensu Takhtajan 1986 and Martínez-Azorín et al. 2023 a) (Fig. 49). For further morphological species characterisation see Dyer (1942 c, 1947), Jessop (1977), and Manning & Goldblatt (2018).
type_taxon
Typus generis: — U. micrantha (A. Rich.) Speta (holotype).
Name
- Synonyms
- sect. Drimia (Speta) J.C.Manning & Goldblatt
- Homonyms
- Urginavia Speta