Gastrodia R. Br.

Description.—Leafless terrestial saprophytes with large tuberous rhizomes. Stems frequently very tall. Stem bracts short and scalelike. Floral bracts more or less ovate. Flowers in a lax terminal raceme. Sepals and petals united into a 5–lobed tube partly split on one side. Labellum shorter than the perianth, adnate at the base, margins variously undulate, lamina with irregular linear calli. Column erect, elongate or short, with or without wings. Stigma orbicular, convex, at the base of the column. Anther terminal, hemispherical. Pollinia 2, bilobed, caudicle absent. Pollen granular.

A genus of some 15 species occurring in Africa, Formosa, Japan, China, India, Malaya, Philippines, Celebes, New Guinea, Australia and New Zealand. Probably Asiatic in origin.