Wednesday, November 14, 2018

[Botany • 2018] Chiloschista pulchella (Orchidaceae: Aeridinae) • A New Orchid Species from Lao PDR


Chiloschista pulchella Aver. & K.S. Nguyen

in Averyanov, Nguyeh & Maisak, 2018.

Abstract
The new species, Chiloschista pulchella (Orchidaceae: Aeridinae) was discovered in Hin Nam No Nature Protected Area, Khammoune Province of the central Laos. The paper provides detailed description and illustration of this species, which is identified as a local endemic of karstic rocky limestone of the northern part of the protected area. It differs from all known congeners in the thin lip, median lip lobe dissected into two small subulate lobules, as well as in large purple blotches on the lip side-lobes never found in other species of this genus. The newly discovered plant represents interest for cultivation as an ornamental plant and needs protection in its natural habitats.

Keyword: Laos, Orchids, Plant diversity, Plant taxonomy, Limestone endemism, Hin Nam No Nature Protected Area


Fig. 1. Chiloschista pulchella Aver. & K.S. Nguyen.
Flowering plant, inflorescence, flowers and floral details (fresh living plant prior to preparation of the holotype herbarium specimen, AL 889).
Photos by Khang Sinh Nguyen and Leonid V. Averyanov, 
correction and design by L. Averyanov.

Fig. 2. Chiloschista pulchella Aver. & K.S. Nguyen.
A. Flowering plant. B. Intact flowers, side views. C. Intact flowers, frontal view. D. Flattened flowers, view from behind and frontal view. E. Intact lip, view from above. F. Intact lip, view from below. G. Intact lip, side view. H. Sagittal section of the lip. I. Anther cap, side view, frontal view and view from below. J. Pollinarium, frontal view, view from behind and side view. K. Halves of pollinium.
 All drawn from the type, AL 889 by L. Averyanov and T. Maisak.

Chiloschista pulchella Aver. & K.S. Nguyen, sp. nov. 

Described from central Laos (“Laos, Khammoune Province, Boualapha District, ..., within the territory of Hin Nam No Nature Protected Area, primary dry evergreen and semi deciduous broad-leaved forest on very steep rocky slope near karstic hill top composed with solid, marble-like highly eroded limestone at 350–430 m a.s.l., epiphyte on tall tree, rare) 
Type (“9 May 2018, L. Averyanov, K. S. Nguyen, T. Maisak, L. Xaiyavongsa, S. Keovankham, AL 889” – LE (holotype).

Distribution: Central Laos: Khammoune province (Boualapha district, the territory of Hin Nam No Nature Protected Area). Endemic. Habitat, ecology and conservation status: Miniature aphyllous epiphytes growing in primary dry evergreen and semideciduous, broad-leaved forests on karstic rocky limestone, at an elevation of 350–430 m. Rare. Currently, the IUCN Red List status should be ascertained as Data Deficient (DD). 

Etymology: The specific epithet refers to the attractive, colorful flowers having purple lip side lobes. 


Notes. Chiloschista pulchella strikingly differs from all its congeners by the flat lip apex (not fleshy), the median lip lobe dissected into two small subulate lobules, and by the presence of large purple blotches on the sidelobes of the lip which is never found in any other species of the genus. This new species belongs to the group of species with a simple operculum (not having any appendages), but has no certain similarity with any other species of this group. Formally, it can be compared with C. exuperei (Guillaumin) Garay, which also has a bilobulate median lip lobe. However, both these species are obviously different in their floral morphology  

    


Leonid V. Averyanov, Khang Sinh Nguyeh and Tatiana V. Maisak. 2018. Chiloschista pulchella (Orchidaceae: Aeridinae) New Orchid Species from Lao PDR. Taiwania. 63(4); 389-392. DOI: 10.6165/tai.2018.63.389