Ceropegia cordifolia M.G.Gilbert

Goyder, D. J., Gilbert, M. G. & Venter, H. J. T. (2020). Apocynaceae (part 2). In: M. A. García (ed.), Flora Zambesiaca, Vol. 7(3). Royal Botanic Gardens, Kew.

Diagnosis

Most closely related to C. emdenpienaariiBruyns, but differing by the uniformly minutely puberulent stems and leaves (not glabrous) and the distinctly cordate leaf base (not truncate to subcordate); these two species are related to C. racemosa but differ most obviously by the short prostrate stems, broadly ovate to cordate leaves and almost flat corolla lobes which are abaxially coarsely adpressed hairy.

Type

Zimbabwe, N: Mazoe, Umvukwes, Ruorka Ranch, fl. 16.xii.1952, Wild 3912 (K001400202 holotype).

Morphology Roots

Roots clustered, fleshy, fusiform, up to 11 cm long, c.5 mm thick

Vegetative Multiplication Tubers

Tuber absent

Morphology Stem

Stem prostrate, mostly unbranched, to 10 cm long, uniformly sparsely minutely puberulent

Morphology Leaves

Leaves ± fleshy; petiole to 10 mm long, puberulous; leaf blade broadly ovate, to 27 × 17 mm, base cordate, margin entire, apex acuminate, abaxial surface paler, both surfaces uniformly minutely puberulent

Morphology Reproductive morphology Inflorescences

Inflorescence mostly concealed beneath leaves, extra-axillary; peduncle to 5 mm long, sparsely puberulent, cyme umbel-like, rachis very short to absent; 2- or 3-flowered, flowers opening in succession

Morphology Reproductive morphology Flowers Pedicel

Pedicel 4–8 mm long, occasionally with a few hairs, often apparently glabrous

Morphology Reproductive morphology Flowers Calyx

Sepals linear-lanceolate to lanceolate, c.2.5 × 0.7 mm wide, slightly recurved, pilose

Morphology General Buds

Bud cylindrical, with flat sinuses

Morphology Reproductive morphology Flowers Corolla

Corolla c.14 mm long, abruptly curved at right angle above basal inflation; tube c.11.5 mm long, basal chamber indistinct, c.4 mm wide, limb cylindrical, c.2.3 mm wide, widening very slightly at mouth; exterior mostly whitish with faint purplish stripes, denser towards apex, darkening with age, pubescent towards mouth, interior glabrous; sinuses acute, flat; lobes oblong, c.2.5 mm long, mostly flat with shallowly revolute margins, apices connate to form subglobose cage, slightly wider than mouth, abaxially dull purple, coarsely adpressed pubescent, adaxially glabrous

Morphology Reproductive morphology Flowers Corona

Corona subsessile, taller than wide; outer corona lobes laterally confluent with bases of inner lobes, deeply bifid, almost to base, teeth triangular, erect, slightly incurved, densely ciliate; inner lobes incumbent-erect, linear, much exceeding staminal column, apices recurved, glabrous

Morphology Reproductive morphology Seeds

Follicles and seed not recorded.

Distribution

Zimbabwe. Endemic

Ecology

Shallow soil among rocks on top of chromium rich dyke; 1600–1650 m.

Conservation

VU: Apparently of very restricted distribution and thus potentially vulnerable particularly to any development of mining.