Ceropegia cupulata (R.A.Dyer) Bruyns

Bruyns, Peter V., Klak, Cornelia & Hanáček, Pavel, 2018, An account of Ceropegia sect. Chamaesiphon (Apocynaceae) in Moçambique with new records and two new species, Phytotaxa 364 (2), pp. 111-135 : 123-125

Ceropegia cupulata (R.A.Dyer) Bruyns ( Figs. 11 , 12 )

Ceropegia vahrmeijeri ( Dyer 1971: 378) Bruyns in Bruyns et al. (2017: 37), syn. nov. Brachystelma vahrmeijeri Dyer.

The widely distributed Ceropegia cupulata was described from a collection of Robert Story made in January 1958 near the Aha Hills in north-eastern Namibia and close to the border with Botswana. It had been collected earlier by Dinter near Rehoboth in central Namibia and is widespread in Namibia ( Bruyns 2014) in flat savanna on Kalahari sands. There are a few records from Botswana and it extends into the same habitat in the Kuruman and Vryburg districts of the former Cape Province of South Africa (NBG, PRE records).

Generally these are inconspicuous, low-growing plants rarely taller than 12 cm, with many finely pubescent to almost glabrous leaves and yellow-green flowers in small clusters next to the nodes. Typically the lobes are narrowly deltate, ascending to widely spreading around a short tube that just contains the similarly coloured, cup-shaped gynostegium. This structure consists of a fused outer series of lobes, usually with a few hairs on the inside and very short inner lobes that project inwards from this cup and just touch the backs of the anthers near their bases.

Ceropegia vahrmeijeri was described from plants collected in September 1965 by Johannes Vahrmeijer in northern Kwazulu-Natal about 3 km from the coast in pale sands among grasses ( Dyer 1971). One other specimen exists from the Makhatini Flats near this area (BOL records). The records cited below are the first from Moçambique ( Fig. 12 ). One was made in January 2001 by the first author and it was gathered again to the south of Maputo by members of a SABONET expedition in November 2001. All records of this species are from the coastal sands at altitudes of less than 100 m over a distance of 250 km from southern Moçambique to north-eastern South Africa. The collection Bruyns 8532 was found on whitish sand among clumps of grass, dwarf and stunted trees of Commiphora Jacquin (1797: 66) , Hyphaene coriacea Gaertner (1788: 13) and Phoenix reclinata Jacquin (1800: 27) , with Crassula schimperi Meyer (1842: 56) , Ceropegia longidens (Brown 1895: 324) Bruyns in Bruyns et al. (2017: 29) and a species of Polygala Linnaeus (1753: 701) .

Ceropegia vahrmeijeri is very similar to C. cupulata . Ceropegia cupulata was figured in Bruyns (1984, 2014), with material from Botswana and Namibia. Plants from Namibia generally have slightly broader flowers that open widely to nearly flat (10–18 mm diam.) with linear lobes and a cupular corona that may be circular in outline. Material shown in Bruyns (2014) from Botswana has a pentagonal outer coronal cup ± 1 mm tall exactly as shown here for the Moçambican collection Bruyns 8532 ( Fig. 11 ), where the flowers were campanulate, 7–8 × 7–9 mm (with a tube 2–3 mm long), with the lobes 4–5 mm long and only slightly spreading (not as widely spreading as those from Botswana and Namibia). This small difference in the degree to which the corolla-lobes spread out is insufficient to keep them separate and so C. vahmeijeri is placed in synonymy under C. cupulata . Ceropegia cupulata then has an unusual distribution: savanna on Kalahari sands of Botswana and Namibia extending with the same habitat into north-central South Africa and then in the coastal sands of northern Kwazulu-Natal.

The specimen Bruyns 8532 from Moçambique was sequenced and belongs to the ‘Kalahari-group’ ( Bruyns et al. 2015) as do C. albipilosa and C. tavalla .

Figures

FIGURE 11. Ceropegia cupulata. A, B, side view of flower (scale 2 mm); C, side view of dissected flower (scale of A = 2 mm); D, oblique view of gynostegium (scale 1 mm); E, pollinarium (scale of D = 0.25 mm). Drawn from: Bruyns 8532 (BOL, E, K).

FIGURE 12. Known distribution of Ceropegia cupulata in Moçambique.