Ceropegia emdenpienaarii Bruyns, 2018

Bruyns, Peter V., 2018, New species of Ceropegia (Apocynaceae) from Africa, Phytotaxa 375 (3), pp. 214-220 : 216-217

Ceropegia emdenpienaarii Bruyns , spec. nov. ( Figs. 2 , 4 B )

This species differs from C. carnosa Meyer (1837:193) by the thicker, trailing shoots, by the 1- to 2-flowered inflorescences and by the much lesser inflation of the corolla-tube towards its mouth.

Type: –– SOUTH AFRICA, Mpumalanga, Lydenburg district, Abel Erasmus Pass, 1600–1750 m, 2 January 1997, P. V.Bruyns 7016 (holotype BOL!, isotype MO).

Slender creeping succulent perennial arising from cluster of swollen fusiform roots. Shoots usually several from rootstock, slightly fleshy, trailing on soil to 0.2 m long and re-rooting in crevices, 2–3 mm thick, not twining, glabrous, green sometimes suffused with purple; leaves 10–25 × 7–15 mm, ovate to ovate-lanceolate, acute, flat, slightly fleshy, glabrous, greyish green, with petiole 6–20 mm long. Inflorescence glabrous, 1- to 2-flowered, with short peduncle 2–6 mm long, with several small bracts at apex; pedicel 6–10 × ± 1 mm, green suffused with purple, ascending; sepals 2–3 mm long, 1 mm broad at base. Corolla tubular with lobes remaining fused at tips, 16–22 mm long; outside pale green with small white patch at base, glabrous; inside dark maroon in basal inflation of tube and green above with white hairs each arising on a small dark maroon papilla, on lobes pale green (sometimes with darker veins) each with maroon patch near apex, with white hairs ± 1.5 mm long along midrib and otherwise glabrous; tube 13–18 mm long, with basal inflation ± 4–8 × 4–6 mm, slightly narrowing to 2.5–4 mm diam. then widening gradually to 4–5 mm at mouth; lobes 2.5–5 mm long, slightly folded longitudinally, ovate, 2–5 mm broad at base narrowing slightly in upper half. Corona 2.5–3.5 × 3–3.5 mm, without basal stipe, fitting tightly into lowest part of tube and fused to base of tube; outer lobes 1–1.5 mm tall, erect, broadly notched in middle right to base into two obtusely deltate lobules touching each other at tips, translucent with dark maroon margins, with many straight white hairs <1 mm long along margins; inner lobes 2– 3.5 mm long, <0.5 mm broad, adpressed to backs of anthers then rising together in column over centre of gynostegium and sometimes diverging above, cream with dark maroon base, obtuse, glabrous. Follicles and seed unknown.

Habitat and Distribution: ––In Zimbabwe it has been recorded in the Umvukwe Range (the Great Dyke) and in the Chimanimani Mountains, while in South Africa it is known in the mountains to the north and south of the Olifants River in the Lydenburg district of Mpumalanga. Plants are usually tightly wedged into crevices in rocky outcrops or cliffs with the shoots running for short distances along a ledge and then rooting and forming another plant, sometimes hanging from ledges. This new species has been known at least since 1952. Plants from one of these collections (Pienaar & LaFon s.n. ( PRE)) were shown in Dyer (1983: 184, 185, fig. 93 A) under the name Ceropegia racemosa subsp. setifera Huber (1957: 96 = C. carnosa ), as a ‘dwarf, alpine’ form of the otherwise far more vigorous forms of this subspecies found at lower altitudes.

Discussion: –– Ceropegia emdenpienaarii belongs to sect. Carnosa Bruyns (2017: 430) and differs from C. carnosa (including C. racemosa Brown 1895: 262 ) mainly in vegetative features: C. carnosa has a slender stem which climbs and twines to 2 m or more, branching freely above. The present new species has short, more succulent shoots which creep on the ground. The inflorescence in C. carnosa is richly branched and many-flowered, unlike the small inflorescences here which produce only one or two flowers. The corolla-tube in C. carnosa is often (though not always) constricted around the middle and it is much broader (more than twice as broad) at its mouth than the tube in C. emdenpienaarii . This species is named after the late Emden A. Pienaar, who first brought it to the attention of botanists at PRE.

Conservation Status. Not threatened since it is known from several localities over a wide area (NT, IUCN 2010).

Figures

FIGURE 2. A, portion of plant (scale 10 mm). B, C, D, corolla (scale 4 mm). E, F, dissected corolla tube with side view of gynostegium (scale 2 mm). G, side view of gynostegium (scale 1 mm). H, I, pollinarium (scale 0.25 mm). A, B, C, E, H drawn from P.V. Bruyns 7016 (BOL); D, F, G, I from Great Dyke, Zimbabwe, D.M. Cumming 46 (no specimen).

FIGURE 4. A, Ceropegia capensis, Bruyns 13117 (BOL).B, Ceropegia emdenpienaarii, Bruyns 7016 (BOL).C, Ceropegia tundavalensis, Bruyns 13303 (BOL). Photographs by P.V.Bruyns.