Ceropegia gypsophila Thulin

Thulin, M. 2009. New species of Caralluma and Ceropegia (Apocynaceae: Asclepiadoideae-Ceropegieae) from eastern Ethiopia. Kew Bulletin 64: 477. DOI: https://doi.org/10.1007/s12225-009-9125-3

Type

Ethiopia, Somali National Regional State, Harerge, 7 km E of KebriDehar, Thulin, Kaariye & Wilhelmi 11418 (holotypus ETH; isotypi K, UPS).

Morphology General Habit

Climber up to c. 2 m tall, with fleshy roots; latex clear; stems herbaceous, succulent, twining, up to c. 5 mm in diam., glabrous, glaucous, greyish green

Morphology Leaves

Leaves with petiole up to 10 mm long, cylindrical and with a furrow above, with short crisped hairs on upper surface; blades lanceolate to narrowly ovate, 15 – 40 × 5 – 15 mm, cuneate to truncate or slightly cordate at the base, acute to acuminate at the apex, with narrowly reticulate venation, the midrib often with short crisped hairs below, margin often ± revolute, pale, with short crisped hairs

Morphology Reproductive morphology Flowers

Flowers 5-merous in axillary few-flowered umbel-like cymes; peduncle 10 – 25 (– 30) mm long, glabrous; pedicel up to 20 (– 30) mm long, glabrous; bracts and bracteoles linear, up to 3 mm long, glabrous. Sepals linear-lanceolate, 3.5 – 5 mm long, 1 – 1.5 mm wide at the base, ± appressed to base of corolla, glabrous or with a few hairs

Morphology Reproductive morphology Flowers Corolla

Corolla ascending, strongly curved near the base, 40 – 50 mm long in total; basal swelling ovoid, c. 6 mm wide and 7 mm long, pale green and glabrous outside, densely pubescent inside, not separated from rest of tube by an annulus; rest of tube pale green in lower narrow part, whitish and with purplish marks in upper expanded part, the lower part cylindrical c. 3 mm wide and c. 6 mm long, strongly curved, pale green, glabrous outside and inside, the upper part broadly funnel-shaped, 10 – 12 mm long and widened to c. 15 mm at the mouth, glabrous outside, densely pubescent with long downwardly pointing hairs inside; corolla lobes whitish with greenish marks, with broadly triangular base tapering to a c. 1.5 mm wide and c. 6 mm long narrow part, with wide rounded openings in between the lobes, then widened again and united to form a flat glabrous broadly 5-lobed roof, 25 – 30 mm in diam., greenish outside and with greenish marks inside, in the centre with a 4 – 5 mm long and 1 – 1.2 mm wide cylindrical greenish beak, on the inside with an umbrella-like 5-lobed structure, c. 8 mm in diam., white and strongly marked with dark purple, formed by 5 ovate fleshy lobes c. 4 × 3 mm, standing together and loosely united, each with a white linear stalk c. 2 × 0.8 mm

Morphology Reproductive morphology Flowers Corona

Corona gynostegial; outer corona cup-shaped with spreading broadly triangular c. 0.8 mm long interstaminal lobes notched at the apex, glabrous; inner corona of linear c. 3 mm long staminal lobes, connivent over the style cap and with outcurved tips

Morphology Reproductive morphology Fruits

Follicles terete, widely divergent, up to 170 × 5 mm, slightly curved, tapering at the tips

Morphology Reproductive morphology Seeds

Seeds pear-shaped in outline, c. 6.5 × 3.5 mm, brown, with a c. 0.5 mm wide pale brown corky marginal wing; coma of c. 25 mm long white hairs

Distribution

Ceropegia gypsophila is known only from a small area east of KebriDehar in the Somali National Regional State (previously Harerge Region) of Ethiopia.

Ecology

Acacia-Commiphora bushland on gypsum; c. 550 m. Kleinia gypsophila J.-P. Lebrun & Stork, previously only known from the type collection from c. 6°N, 44°10′E, was also seen in the locality.

Conservation

Several individuals were seen, but all within a single gypsum outcrop less than 1 km in diam. and surrounded by silty or sandy ground. The grazing pressure in the area seemed high, and even if it is likely that further populations of the species exist, it should be regarded as Critically Endangered (CR B1 B2a, biii D).

Note

Ceropegia gypsophila is very different from all other species of the genus found in the Horn of Africa region. Its nearest relative in this region is probably C. somalensisChiov., distributed in Somalia, Ethiopia and Kenya, a species with a similar corona structure and a corolla with apical parts of lobes sometimes cohering to a club-shaped beak, but nothing like the large flattened roof formed by the upper parts of the corolla lobes in C. gypsophila. More similar, at least superficially, is the little-known C. galeata H. Huber from coastal parts of Kenya. This has corolla lobes forming a roof, but the corolla tube is swollen in the entire lower half and glabrous inside, the lobes are ciliate with purplish, vibratile hairs, and the inner corona lobes are only slightly longer than the outer ones and have erect tips. These marked differences make a close relationship between C. gypsophila and C. galeata unlikely. Instead, it seems quite obvious that the closest relative of C. gypsophila is C. sandersoniiDecne. ex Hook. f. in southern Mozambique, Swaziland and north-eastern South Africa. C. gypsophila and C. sandersonii are very similar in their large, parachute-like flowers with a flattened roof formed by the upper parts of the corolla-lobes, and they also basically agree in leaf shape, shape of corolla tube, as well as in the structure of the corona.