Distribution pattern of orchids in Uttarakhand, Western Himalayas, India

Orchids are widely distributed in tropics, subtropics and temperate regions. Within the tropics, orchids form an important feature of the vegetation, chiefly as epiphytes. India’s epiphytic orchid is to be found primarily in the Eastern Himalayas and Western Ghats, while the terrestrial species flourishes in the Western Himalayas. In the state of Uttarakhand, India, orchid distribution is not homogeneous. Orchids are typically concentrated along the riverine areas and in pockets of moist forests where there is suitable habitat for their growth, development and regeneration. The purpose of this study was to provide a general review of the distribution of orchid species (epiphytic and terrestrial) in Uttarakhand. A total of 240 species (of which 10 are endemic) belonging to 73 genera were recorded. The largest number of orchid species (terrestrial and epiphytic) were encountered in the sub-tropical zone (<1500 m). Terrestrial orchids were distributed throughout the altitudinal gradient, but the largest number of species occurred in two ecotones between high and low altitude forests (1500-2000 m and 3000-3500 m). Twenty-one species were restricted to a particular habitat.