Abstract
We recently found two populations of Gastrodia (Orchidaceae) similar to G. shimizuana, G. hiemalis and G. pubilabiata on Iriomote Island in the Ryukyu Islands. Gastrodia shimizuana is a mycoparasitic orchid collected on Iriomote Island and known only from the type. Gastrodia pubilabiata is also a rare species for which no detailed morphological observations have been made. Gastrodia hiemalis appears to be closely related to G. pubilabiata and is endemic to Taiwan. Morphological variation based on population samples of our unknown Gastrodia and G. pubilabiata is reported here. The unknown Gastrodia can be distinguished from G. pubilabiata by the dimensions of the floral parts, the shape of the petals and lip, and floral color. Since our collection differs only in minor features from the original description of G. shimizuana we consider it to be that species.
