First Record of the Mycoheterotrophic Plant Gastrodia clausa (Orchidaceae) from Okinawa Island, Ryukyu Islands, Japan

Abstract

Flowering individuals of a species of Gastrodia (Orchidaceae) with a closed perianth tube, a petaloid lip without appendages or calluses, and a column with a large, bifid ventral appendage were discovered in the northern part of Okinawa Island, Okinawa Prefecture, the Ryukyus. This combination of characters is known only in Gastrodia clausa, a recently described species from Taiwan. The characteristics of the Okinawan plants agree with the description of G. clausa. We therefore conclude that our plants represent the first record of G. clausa in Japan.