Gymnanthemum Cass.

Robinson, Harold & Funk, Vicki A., 2014, Gymnanthemum koekemoerae (Compositae, Vernonieae), a new species from South Africa, PhytoKeys 36, pp. 59-65 : 60

Gymnanthemum Cass.

Gymnanthemum Bull. Soc. Philom. Paris 1817: 10. 1817. Type: Gymnanthemum cupulare Cass. = Gymnanthemum coloratum (Willd.) H. Rob. & B. Kahn

Bracheilema R. Br. ex Salt, Abyss. Append.: 65. 1814, nom. nud.

Decaneurum DC., Arch. Bot. (Paris) 2: 516. 1833, nom. superfl., type same as Gymnanthemum .

Plectreca Raf., Fl. Tellur. 4: 119. 1838. Type: Staehelina corymbosa Thunb.

Keringa Raf., Sylva Tellur.: 144. 1838. Type: Vernonia amygdalina Del.

Cheliusia Sch. Bip. in Hochstetter, Flora 24(1, Intelligenzbl.): 26. 1841, nom. nud.

Vernonia subsect. Urceolata S.B. Jones, Rhodora 83: 67. 1981. Type: Vernonia sphaerocalyx O. Hoffm.

Remarks.

Shrubs or small trees moderately to densely branching; stems often felted, hairs rarely asymmetrically T-shaped. Leaves alternate; petioles short, winged or elongate; blades membranaceous to rather coriaceous, margins entire to serrate or dentate, upper surfaces essentially glabrous and somewhat glossy to arachnoid tomentose. Inflorescences terminal, densely corymbiform, with small bracteoles; peduncles short; involucral bracts coriaceous, 25-35, 4-5-seriate, inner bracts often deciduous. Florets 3-50; corolla white to violet, anther base broadly tailed, tails often long, apical appendage glabrous; style base without or with scarcely distinct node; style branches with stout, pointed sweeping hairs. Achenes 5-10-costate, raphids short, elongate or not evident; pappus of many rather persistent capillary bristles, often with broadened tips, with outer series of short squamellae. Pollen sublophate. Chromosome number n = 10, 20. More than 43 species are found in sub-Saharan Africa, Madagascar, Southern Asia, and also introduced into Brazil.

The genus Gymnanthemum was described by Cassini (1817), included in Vernonia by Candolle (1836) and Bentham (1873) and resurrected by Robinson and Kahn (1986) and Robinson (1999). The generic limits have changed and are now more narrow than in 1999. Currently the genus has nine species in southern Africa (Robinson et al. in prep.), five of which are endemic to South Africa; a key to those is provided here. The four more widespread species are Gymnanthemum theophrastifolium (Schweinf. ex Oliv. & Hiern) H. Rob., Gymnanthemum coloratum (Willd.) H. Rob. & B. Kahn, Gymnanthemum amygdalinum (Del.) Sch. Bip. ex Walp. and Gymnanthemum myrianthum (Hook. f.) H. Rob. The still unfinished monograph will cover all species of Vernonieae from Southern Africa with descriptions, keys and pollen images (Robinson et al. in prep.).