Ceropegia macrocarpa (Sprenger) Bruyns, S. African J. Bot. 112: 424 (2017)

Alharbi, Samah A. & Al-Qthanin, Rahmah N., 2021, Taxonomic revision of Ceropegia sect. Huernia (Asclepiadoideae, Apocynaceae) in Saudi Arabia with three new combinations, PhytoKeys 174, pp. 47-80 : 47

1. Ceropegia macrocarpa (Sprenger) Bruyns, S. African J. Bot. 112: 424 (2017) Figs 4 , 5 ; Map 1

Huernia macrocarpa ≡ Huernia macrocarpa Sprenger, Cat. Dammann & Co. 59: 4 (1892) Type: Eritrea • Penzig s.n. ( K epitype) .

Huernia macrocarpa arabica = Huernia macrocarpa var. arabica ( N. E. Brown) A. C. White & B. Sloane (1937)

Huernia macrocarpa penzigii = Huernia macrocarpa var. penzigii ( N. E. Brown) A. C. White & B. Sloane (1937)

Huernia macrocarpa schweinfurthii = Huernia macrocarpa var. schweinfurthii ( A. Berger) A. C. White & B. Sloane (1937)

Huernia penzigii = Huernia penzigii N. E. Brown (1892)

Huernia penzigii arabica = Huernia penzigii var. arabica ( N. E. Brown) A. Berger (1910)

Huernia penzigii schimperi = Huernia penzigii var. schimperi A. Berger (1910)

Huernia penzigii schweinfurthii = Huernia penzigii var. schweinfurthii A. Berger (1910)

Description.

Dwarf succulent forming dense clump. Branches 60 mm long, non-rhizomatous, erect, decumbent, grey-green mottled with purple-red; tubercles up to 10 mm long (including leaf-rudiment), conical, spreading, laterally flattened and joined into 5 angles along branch, each tipped with a soft slender acuminate caducous leaf-rudiment. Inflorescence usually only 1 per branch, arising in lower half of branch, each bearing 2-3 flowers developing mainly successively, flowers with no unpleasant smell; pedicel spreading and holding flower facing horizontally. Corolla 15 mm diam., shallow bowl shape; outside smooth, cream-speckled with maroon, with 1 heavy (+ 2 lighter) raised longitudinal veins running from lobes to base of tube; inside uniformly coloured with purplish-red, covered except in lower third of tube with very small wart-like papillae; tube cupular; lobes ascending, deltoid, acuminate. Corona without basal stipe; outer lobes spreading on base of tube and fused partially to it, discrete to 5-lobed with each lobe subquadrate emarginate or slightly crenate, blackish-maroon; inner lobes maroon, adpressed to backs of anthers exceeding them and meeting in centre, dorsiventrally flattened around laterally broadened base becoming terete above and tapering gradually to obtuse bristly apex, a transversely conspicuously gibbous, broadened at the base with an acute end.

Distribution in Saudi Arabia.

Rare, known only from Asir between Abha and Jabal Sawdah, SW Saudi Arabia ( Chaudhary 2001).

General distribution.

Somaliland, Sudan, Eritrea, Ethiopia, South west Arabian Peninsula ( Saudi Arabia, Yemen) ( Albers and Meve 2002).

Habitat and ecology.

Growing amongst granitic rocks and scattered shrubs on a steep hillside at 2700 m alt. ( Collenette 1999).

Diagnosis.

This species can be easily distinguished from other members of sect. Huernia Huernia in Saudi Arabia by the small maroon bowl-shaped flowers.

Etymology.

Macrocarpus (Greek) 'makros', large; and 'karpos', fruit ( Eggli and Newton 2004).

Preliminary conservation status.

The species is known only from one location near Sawda Mountain; the estimated EOO and AOO of 8 km 2 would place the species in the Critically Endangered ( CR) status. However, little is known about the size of the population and possible threats. Therefore, Data Deficient ( DD) is assigned to this species.

Additional specimens examined.

Ethiopia, Gilbert 2945 ( E [fl in spirit])

Figures

Map 1. Distribution of Ceropegia macrocarpa in Saudi Arabia.

Figure 4. Ceropegia macrocarpa, Jabal Melhan, 20 km E Al Mighlaf, Yemen, ex JRI Wood 1202, sub DP 7571. Reproduced from Plowes (2014).

Figure 5. Ceropegia macrocarpa A branch B side view of dissected flower C papillae inside corolla in mouth of tube D side view of gynostegium. Drawn from photo of ex JRI Wood 1202, sub DP 7571, Jabal Melhan, 20 km E Al Mighlaf, Yemen.