Tropidia


Tropidia, commonly known as crown orchids or as 竹茎兰属 , is a genus of about thirty species of evergreen terrestrial orchids in the family Orchidaceae. They have thin, wiry stems with two or more tough, leaves with a flowering spike at the top of the stem, bearing crowded flowers. Species in this genus are distributed across the warmer parts of both the Eastern and Western Hemispheres.

Description

Orchids in the genus Tropidia are evergreen, terrestrial, sometimes mycotrophic herbs which form small clumps. They have thin, wiry stems, sometimes with a few branches. The stems have two or more thin, tough, pleated, lance-shaped to egg-shaped leaves. Crowded white, greenish or brown, sometimes resupinate flowers are arranged on the top of the stem and have the sepals and petals free from each other, or with the sepals joined and surrounding the base of the labellum. The labellum is not lobed but has a pouch or spur at its base.

Taxonomy and naming

The genus Tropidia was first formally described in 1833 by John Lindley and the description was published in Edwards's Botanical Register. The name Tropidia is derived from the Ancient Greek word tropidos meaning "keel", referring to the boat-shaped labellum of some species in this genus.

Distribution and habitat

Species in the genus Tropidium grow in deep shade in evergreen monsoon forests and are native to China, Japan, the Indian Subcontinent, Indonesia, Indochina, Philippines, New Guinea, Australia, Latin America, the West Indies, Florida, and some Pacific Islands including the Solomons, Fiji, New Caledonia, the Galápagos and Vanuatu.

Species

The following is a list of species of Tropidia recognised by the World Checklist of Selected Plant Families as at October 2018: