Roxb. ex Lindl.
Description
Dendrobium formosum is an epiphytic orchid of the eastern Himalaya and Indo-Burmese region, native to India, Nepal, Bhutan, Myanmar, Thailand and the Philippines; its roughly 88 georeferenced GBIF records also include cultivated material in Europe, the United States and Brazil, reflecting its horticultural popularity. In Nepal it occurs at low to mid elevations, as illustrated by the collection near Arkhet in Gorkha district at about 720 m in May, where it grows on trunks and branches in warm, humid subtropical broad-leaved forest, favouring shaded, mossy bark with high atmospheric humidity.
The species forms erect, cane-like pseudobulbous stems whose leaf sheaths, like the young growth, are clothed in conspicuous blackish-brown hairs, a feature of section Formosae. The leaves are distichous, oblong-lanceolate and leathery. Flowers are borne in short few-flowered racemes near the stem apex and are large and showy, with broad, pure white spreading sepals and petals and a trumpet-shaped labellum marked by a bright yellow or orange throat blotch. The fruit is a ribbed dehiscent capsule releasing dust-like seeds.
Within the vast genus Dendrobium, D. formosum anchors section Formosae, a group of black-haired species prized for their substantial white blooms. As a forest epiphyte dependent on intact canopies and mycorrhizal germination, it is vulnerable to deforestation and over-collection for the ornamental trade, and like all Orchidaceae is listed on CITES Appendix II regulating international commerce in wild-sourced plants.
Author: Roxb. ex Lindl. · Sources: POWO (Kew), GBIF, Flora of China Vol. 25, Flora of Bhutan Vol. 3, Flora of Nepal, The Genus Dendrobium (Lavarack, Harris & Stocker)