Saturday, March 13, 2021

[Botany • 2021] Ceropegia longicaudata (Apocynaceae, Asclepiadoideae) • Taxonomic Study of Ceropegia L. for The Flora of Laos: One New Species and One New Record from central Laos


Ceropegia longicaudata Phonep. & Rodda.

in Phonepaseth & Rodda, 2021. 
ດອກຈິນດາພູເຂົາຄວາຍ || taiwania.ntu.edu.tw 

Abstract
A newly discovered species from central Laos, Ceropegia longicaudata, is here described and illustrated. It is compared with the morphologically similar species Ceropegia cochleata Kidyoo. Ceropegia longicaudata displays clear differences in the leaf pubescence and venation, length of the corolla lobe tips, colour of corolla lobe, and shape of staminal corona lobes. Ceropegia cochleata is newly recorded for the Flora of Laos. A key to the now three species of Ceropegia in Laos is also provided.

Keyword: Ceropegia cochleata, Ceropegia laotica, Ceropegieae, Khammouan, new species, Phoukhaokhouay National Protected Area

Ceropegia longicaudata Phonep. & Rodda.
A. habit; B. open flower; C. longitudinal section of corolla; D. young flower bud; E. corona top view; F. corona side view; G. Pollinarium.
Drawn by P. Phonepaseuth from P005 (FOF).

Ceropegia longicaudata Phonep. & Rodda.
 A. habitat; B. habit; C. leaves adaxial and abaxial side; D. tuber; E. flower bud and open flower; F. longitudinal section of corolla; G. corona top view; H. corona from underneath; I. corona side view; J. pollinarium; K. dry flower (specimen).
Photos by P. Phonepaseuth from P005 (FOF)

Ceropegia longicaudata Phonep. & Rodda, sp. nov.

Diagnosis. Ceropegia longicaudata is similar to C. cochleata in having tuberous rootstock and linear lanceolate laminas. It can be separated by glabrous leaves without distinct nerves (vs. pubescent with distinct nerves in C. cochleata), longer corolla lobe tips (25–30 mm in C. longicaudata vs. 15–20 mm in C. cochleata), colour of corolla lobe completely bright green (vs. basally green with reddish brown apex), and staminal corona lobes distally with recurved diverging apices (vs. straight and converging).

Etymology. The specific epithet ‘longicaudata’ refers to long corolla lobes that characterize this species. 

Distribution. Only known from Phoukhaokhouay National Protected Area, in Laos. It is found at two locations, the type locality in Vientiane Province (Fig, 5), and from a locality 25–30 km eastwards, in Bolikhamxay Province, where it was photographed by Bertrand Laville in 2016 (theceropegiablog.wordpress.com/2016/02/22/anew-locality-for-Ceropegia-cochleata). 

Ecology and habitat. This species rooted in very thin soils over large sandstone boulders growing together with grasses. The plants were climbing over grasses in open areas partially exposed, at 270–300 m a.s.l. Flowering August–September.

 Vernacular name. ດອກຈິນດາພູເຂົາຄວາຍ ‘Dok Chinda Phoukhaokhouay’ [Phoukhaokhouay jewelry flower] (proposed here).

Phongphayboun Phonepaseth and Michele Rodda. 2021. Taxonomic Study of Ceropegia L. (Apocynaceae, Asclepiadoideae) for The Flora of Laos: One New Species and One New Record from central Laos. Taiwania. 66(1); 93-100.