Thursday, December 14, 2017

[Botany • 2017] Nervilia kasiensis • A New Terrestrial Orchid Endemic to Vientiane Province, northern Laos | Studies in Asian Nervilia (Orchidaceae) VII


Nervilia kasiensis  S.W.Gale & Phaxaysombath

Gale & Phaxaysombath, 2017.

 Abstract
A new species belonging to the terrestrial orchid genus Nervilia is described from Kasi District, Vientiane Province, northern Laos. Referable to the widespread and species-rich N. adolphi/punctata alliance on account of its solitary flower, slender white and violet-marked labellum and glabrous, angular leaf, Nervilia kasiensis is morphologically most closely allied to N. muratana of southern China and northern Vietnam. As in that species, the flowering and leafing phases overlap, an unusual feature among members of the genus. The new species can be distinguished from N. muratana by its shorter inflorescence, its weakly spreading perianth with beige sepals, its narrower labellum with a central pubescent strip on the epichile, its arched column, and by its faintly tessellated leaf. A morphological description, line drawing and notes on the species’ ecology and conservation status are presented.

Keywords: Hysteranthy; Laos; Orchidaceae; new species; species complex


Fig. 1  Nervilia kasiensis S.W.Gale & Phaxaysombath. 
a. Plants in leaf at the type locality in northwest Laos showing the faint silver-grey mottling on the adaxial surface; b. plant in flower showing the non-hysteranthous growth habit; c. close-up of inflorescence; d. lateral view of flower showing slightly saccate base of the lateral sepals; e. front view of flower showing the weakly spreading perianth. 

Nervilia kasiensis S.W.Gale & Phaxaysombath, sp. nov.  

Etymology. Named after Kasi District, northern Laos, in which this species was discovered.
  

  

 S.W. Gale and T. Phaxaysombath. 2017. Studies in Asian Nervilia (Orchidaceae) VII: Nervilia kasiensis, A New Lao Endemic.  Blumea - Biodiversity, Evolution and Biogeography of Plants.   62; 1–5. DOI:  10.3767/000651917X694732