Ceropegia cordiloba Werdermann

Heiduk, Annemarie & Styles, David G. A., 2023, Ceropegia strophanthiflora (Apocynaceae-Asclepiadoideae) - a magnificent and rare new species from South Africa at the brink of extinction, Phytotaxa 632 (1), pp. 27-37 : 33-34

Ceropegia cordiloba Werdermann , Bot. Jahrb. Syst. 70(2): 209 (1939).

Basionym : Ceropegia papillata N.E.Brown var. cordiloba (Werdermann) H.Huber, Mem. Soc. Br. 12: 152 (1957).

Type:— TANZANIA. Songea District: Matengo Hills at Litembo , 1500–1600 m, 20 April 1939, H.Zerny 438 (holotype B †; lectotype P [ P00109660 ], designated here) .

Ceropegia tanzaniensis Peckover, CactusWorld 37(3): 174 (2019), syn. nov. Type:— TANZANIA. Njombe Region: Mlangali village, February 2015, R.Peckover 291 (holotype PRU).

Notes: —Still following the traditional genus concept in Ceropegieae , Ceropegia dodomaensis was originally described in Brachystelma as B. tanzaniensis (correctly “ tanzaniense ”), but in accordance with the current proposals to consider Brachystelma as belonging to Ceropegia ( Bruyns et al. 2017; Endress et al. 2018; Goyder et al. 2020), the transfer of this taxon to Ceropegia has become necessary. Curiously, shortly after publishing B. tanzaniense, Ralph Peckover himself published another name, i.e., Ceropegia tanzaniensis Peckover (2019b: 174) , for a taxon from Tanzania, which he placed in Ceropegia based on its kettle-trap flowers typical for Ceropegia s.str. In consequence, this name is no longer available for the transfer of B. tanzaniense to Ceropegia . We therefore here propose the new name C. dodomaensis referring to the area where the type specimen was collected. Based on its vegetative (fleshy, disc-like single tuber, short erect stems) and floral characters (short corolla tube, spreading corolla lobes), C. dodomaensis clearly belongs in section Chamaesiphon .

It appears that the blocking name for the transfer of Brachystelma tanzaniense , i.e., Ceropegia tanzaniensis , was superfluously created as the material described under this name belongs to the already existing taxon C. cordiloba Werdermann (1939: 209) —thus, C. tanzaniensis is reduced to a synonym of this species. Ceropegia cordiloba , described by Erich Werdermann in 1939, was not accepted as a species by Huber (1957) who treated it as C. papillata var. cordiloba (Werderm.) Huber (1957: 152) in his revision of Ceropegia ; also, Bruyns et al. (2017) did not accept the species status of this taxon. However, C. cordiloba (incl. C. tanzaniensis ) was recollected several times over the last years, and these recollections show little variation and do not differ from the type collection of 1939. The broadened and roof-shaped fused corolla lobe tips are an unmistakable distinguishing feature of this Tanzanian endemic. We therefore follow the proposal by Masinde in Goyder et al. (2012: 236) that C. cordiloba is indeed a good species and hereby reinstate it as such. Finally, lectotypification becomes necessary because the holotype was destroyed in Berlin (B). The duplicate specimen lodged in Paris (P) is the only available type material and has to serve as lectotype.

Additional material examined

Ceropegia cordiloba :— TANZANIA. Dodoma Region: Mpwapwa District, Rubeho Mts , Wotta Forest Reserve , 22 March 2017, A.Hemp 6777 ( UBT) .