Tuesday, February 7, 2017

[Botany • 2017] Ceropegia digitiformis sp. nov. (Apocynaceae, Asclepiadoideae) from northeastern Thailand


Ceropegia digitiformis Kidyoo


ABSTRACT
 A new species, Ceropegia digitiformis Kidyoo, was discovered from northeastern Thailand. It is here described and illustrated. Photographs and a diagnostic comparison with the morphologically similar related species, Ceropegia thwaitesii Hook., are also provided. These two species display clear difference in shapes and pubescence of the corona lobes.

 KEY WORDS: Apocynaceae, Asclepiadoideae, Ceropegia, northeastern Thailand


Fig. 2. Photographs showing habitat, vegetative and reproductive parts of Ceropegia digitiformis Kidyoo: A. habitat (Phu Langka National Park), B. flowering branch, C. long section of flower, G. side view of gynostegium, H. top view of gynostegium.  

Ceropegia digitiformis Kidyoo, sp. nov.  

Ceropegia digitiformis can be distinguished from C. thwaitesii by its outer corona of the same length as inner corona, glabrous outer coronal lobe whose apex is deeply bifid with linear-lanceolate segments, and linear-lanceolate inner corona lobes.

Fig. 2. Photographs showing habitat, vegetative and reproductive parts of Ceropegia digitiformis Kidyoo: A. habitat (Phu Langka National Park), B. flowering branch, C. long section of flower, D. calyx, E. pollinarium, F. underground stem with small tubers, G. side view of gynostegium, H. top view of gynostegium. 

Etymology: The specific epithet ‘digitiformis’ refers to the finger-like structure of the outer corona, brought about by division of each outer corona lobe at the apex extending through most of its whole length into two segments. Each segment is linear-lanceolate, subterete, slightly compressed with a blunt apex (Fig.1C & 2G)


Manit Kidyoo and Chanita Paliyavuth. 2017. Ceropegia digitiformis sp. nov. (Apocynaceae, Asclepiadoideae) from northeastern Thailand. 
Taiwania. 62(1): 24‒28.    DOI:  10.6165/tai.2017.62.24