Wall. ex Lindl.
Description
Dendrobium amoenum Wall. ex Lindl. is an epiphytic orchid distributed across the central and eastern Himalaya and adjacent ranges, with records (GBIF: c. 147 occurrences) from India, Nepal, Bhutan and Myanmar, extending into the Malesian region (Indonesia). It is a characteristic element of humid temperate and subtropical broad-leaved forests, growing on mossy trunks and branches at roughly 1,000–2,000 m. The photographed material from Nepal's Helambu region in the Indrawati Valley, at about 1,500 m and flowering in May, falls squarely within its preferred mid-montane belt, where seasonal monsoon humidity and cloud-forest conditions favour epiphytic growth.
The species forms slender, pendulous, terete stems up to 30–60 cm long, often becoming leafless before flowering and bearing thin internodes. The leaves are distichous, lanceolate and deciduous, leaving conspicuous nodal sheaths. Flowers are borne singly or in small clusters from the nodes of older canes, are fragrant, and measure roughly 3–4 cm across. The sepals and petals are white, frequently tinged or tipped with pale rose-purple, while the rounded, pubescent lip is white with a yellow to greenish central disc and a fine purple apical margin. The column is short, bearing four pollinia within an operculate anther cap.
Dendrobium amoenum belongs to the large, taxonomically complex genus Dendrobium (section Dendrobium), members of which display the characteristic deciduous habit and nodal flowering. Like many Himalayan epiphytic orchids it is sensitive to deforestation and to collection pressure, and the genus is listed under CITES Appendix II. The input family "Orchideaceae" is an orthographic variant of the accepted Orchidaceae.
Author: Wall. ex Lindl. · Sources: POWO (Kew), Flora of Bhutan Vol. 3, Flora of Nepal, GBIF, Pearce & Cribb: The Orchids of Bhutan (2002)