Plants perennial, leafless, dwarf, succulent herbs, usuallly mat-forming rarely rhizomatous, sometimes prostrate or pendulous; branches glabrous, smooth, 4- to 16-angled. Leaves usually reduced to soft points, without stipules, borne on raised tubercles formed by the much swollen leaf-bases; tubercles arranged in rows along the branches, forming the branch angles and a groove between adjacent rows of tubercles. Inflorescences glabrous, with 1-10 flowers, usually only one per branch, arising mainly in lower half of the branches between tubercles. Corollas urceolate to campanulate or subrotate, shallowly lobed; staminal coronas in two well-separated series, inner series pressed to backs of anthers, mostly exceeding them and meeting in centre, often with prominent transversely-rounded dorsal projections; outer series spreading along base of tube, discrete to fused into spreading discs with fleshy tubercles beneath guide-rail obscuring entrance to small nectarial cavity; anthers horizontal, on top of style-heads, margins shrinking back to expose pollinia, rectangular; pollinia ellipsoidal, longer than broad, insertion-crest exactly along outer edge, caudicle attached with broad cupular pad to base. Follicles erect, terete-fusiform, obclavate, slender, consisting of two horns diverging at 30–60°, longitudinally mottled with narrow broken purple stripes, glabrous, smooth.
Reference
Alharbi SA, Al-Qthanin RN (2021) Taxonomic revision of Ceropegia sect. Huernia (Asclepiadoideae, Apocynaceae) in Saudi Arabia with three new combinations. PhytoKeys 174: 47-80.
Citations in Alharbi et al. :
Bruyns PV (2005) Stapeliads of Southern Africa and Madagascar (Vol. 1). Umdaus Press, South Africa, 330 pp.
Bruyns PV (2014) The Apocynaceae of Namibia. South African National Biodiversity Institute, Pretoria, 158 pp.
Bruyns PV, Klak C, Hanáček P (2017) A revised, phylogenetically-based concept of Ceropegia (Apocynaceae). South African Journal of Botany 112: 399–436. https://doi.org/10.1016/j.sajb.2017.06.021