Studies in Asian Nervilia (Orchidaceae) VII: Nervilia kasiensis, a new Lao endemic

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, N. 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.