Ceropegia sect. Chamaesiphon, Huber, 1957

Heiduk, Annemarie, Crouch, Neil R. & Styles, David G. A., 2023, Ceropegia gilboaensis (Apocynaceae), a new species from the Midlands of KwaZulu-Natal, South Africa, Phytotaxa 591 (2), pp. 125-136 : 134

The following key distinguishes the 10 brood-site mimicking species of Ceropegia sect. Chamaesiphon

which occur in KwaZulu-Natal and may be confused with C. gilboaensis :

1. Stems prostrate...................................................................................................................................................................................2

- Stems sub-erect to erect......................................................................................................................................................................6

2. Flowers flat or shallowly campanulate, fused portion of corolla ±1/3 or less...................................................................................3

- Flowers steep cylindrical-campanulate, fused portion of corolla ±1/2..............................................................................................4

3. Corolla flat or shallowly saucer-shaped, glabrous..............................................................................................................................5

- Corolla campanulate, with white trichomes on upper surface ............................................................................................. C. remota

4. Corolla lobe bases purple mottled, distinctly fluted, mouth 5-star-shaped, corona lobes not covering the style head.. C. ngomensis

- Corolla lobe bases with broken, transverse, burgundy bands, mouth not 5-star shaped, corona lobes covering style head................ ....................................................................................................................................................................................... C. gilboaensis

5. Corolla flat, less than ± 12 mm in diameter ................................................................................................................... C. pulchellior

- Corolla shallowly saucer-shaped, 17–20 mm in diameter..................................................................................................... C. coddii

6. Corolla glabrous .......................................................................................................................................................... C. modestantha

- Corolla papillate or with trichomes on upper surface........................................................................................................................7

7. Corolla bowl-shaped, fused portion of corolla ±1/2...................................................................................................... C. chlorozona

- Corolla (shallowly) campanulate, fused portion of corolla ±1/3 or less............................................................................................8

8. Leaves narrowly elliptic-lanceolate, trichomes on upper corolla surface ......................................................................... C. australis

- Leaves ovate to elliptic to lanceolate, with or without trichomes on corolla lobe margins...............................................................9

9. Flowers 2–several, corolla papillate, rugose ........................................................................................................................ C. perdita

- Flowers solitary, corolla margins with long trichomes, tubers finger-like, irregularly shaped...................................... C. petrophila