Ceropegia tundavalensis Bruyns, 2018

Bruyns, Peter V., 2018, New species of Ceropegia (Apocynaceae) from Africa, Phytotaxa 375 (3), pp. 214-220 : 217-219

Ceropegia tundavalensis Bruyns spec. nov. ( Figs. 3 , 4 C )

This species differs from C. blepharanthera (Huber: 1961: 33) Bruyns (2017: 433) by the smaller flower with longer corolla-tube and the short inner coronal lobes which only slightly exceed the anthers.

Type: –– ANGOLA, Huila Prov., Lubango distr., Tundavala Nature Reserve, 2250 m, 15 Jul. 2010, A.Harrower 4413 (holotype BOL!).

Small erect geophytic perennial arising from flattened discoid tuber 10–30 mm diam. Stem usually solitary, 20–60 mm tall, ± 1 mm thick, erect and usually simple, finely pubescent, reddish green; leaves 6–12 × 2–5 mm, ovate to narrowly ovate-lanceolate, obtuse and minutely apiculate, slightly folded upwards, not fleshy, finely pubescent, green, tapering into short petiole 1–3 mm long. Inflorescence minutely pubescent, bearing 1 or 2 flowers in short succession without peduncle or bracts; pedicel 2–3 × ± 0.5 mm, reddish green, ascending; sepals 1.2–1.8 mm long, <0.5 mm broad at base, green, glabrous. Corolla campanulate with lobes ascending or spreading above tube, 3.5–4.5 × 4.5–6 mm; outside white becoming green near tips of lobes, finely pubescent except near base; inside base of tube white and glabrous, mouth of tube and lower halves of lobes white with red papillae each tipped with a white club-shaped hair <0.5 mm long, upper halves of lobes green; tube 1.5–2 mm long, cupular; lobes ± 3 mm long, slightly folded longitudinally towards slightly swollen tip, ± 1.2 mm broad at base. Corona ± 1.5 × 1.5 mm, pale green, glabrous, without basal stipe; outer lobes ± 0.6 mm tall, forming slender bays below bases of guide-rails, very slightly notched in middle; inner lobes ± 0.6 mm long, ± 0.2 mm broad at bases, adpressed to backs of anthers then rising slightly beyond the and slightly exceeding them, obtuse to acute. Follicles and seed unknown.

Habitat and Distribution: ––This minute geophyte is only known on patches of shallow ground overlaying flat slabs of sandstone close to the edge of the escarpment. During the summer months the rainfall is high and this soil is constantly wet from seepage and run-off from nearby higher places (which are covered with short scrub dominated in places by Proteaceae ). These patches are inhabited by mosses, small geophytes like this new species, Dipcadi Medikus (1790: 431) , Eriospermum Jacquin (1796: 72 , tiny sedges and Crassula vaginata Ecklon & Zeyher (1837: 298) In habitat the plants rarely exceed 30 mm tall, though in cultivation they may become a little larger.

Discussion: ––With its flattened-discoid tuber, short, deciduous stem and small, only slightly tubular flowers, C. tundavalensis is clearly a member of sect. Chamaesiphon Huber (1957: 34) . At present, the following five species of this section are known from Angola: C. dinterana Bruyns (2017: 433) , C. pruinosior Bruyns (2017: 435) , C. pygmaea Schinz (1888: 265) , C. recurviloba Bruyns (2017: 435) and C. sabuliphila Bruyns (2017: 435) so this new species brings the number to six.

The small green and white flowers of Ceropegia tundavalensis remind one of the Namibian endemic C. blepharanthera , which also has hairs inside the corolla around the mouth of the tube and similarly shaped outer coronal lobes. However, in C. blepharanthera ( Bruyns 1995) the corolla-lobes are longer, the tube is shorter and the inner coronal lobes are usually at least twice as long, with rounded swollen tips that often (though not always) spread widely above the anthers. Ceropegia blepharanthera also has a turnip-shaped tuber while this new species has a flattened, discoid tuber.

Conservation Status. Only known from two gatherings therefore considered to be Vulnerable (V, IUCN 2010).

Figures

FIGURE 3. Ceropegia tundavalensis. A, B, corolla (scale 2 mm). C, D, base of dissected corolla tube with side view of gynostegium (scale 1 mm). E, papillae near mouth of tube (scale 0.5 mm). F, pollinarium (scale 0.25 mm). A, C, E, F drawn drawn from A.Harrower 4413 (BOL); B. D, drawn by P.V.Bruyns from P.V.Bruyns 13303 (BOL).

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.