2022 年 73 巻 3 号 p. 211-217
Gastrodia (Orchidaceae) is a species-rich, achlorophyllous genus containing more than 100 species. Recently, several species of Gastrodia with only closed, self-pollinating, cleistogamous flowers were discovered in Japan and Taiwan. Here, an additional taxon of Gastrodia with completely cleistogamous flowers from a lowland evergreen forest on Yakushima, Japan, is described as G. takeshimensis Suetsugu var. shirataniensis Suetsugu. It is most similar to G. takeshimensis var. takeshimensis, but is distinguishable by its peloric labellum and column with a prominent ventral appendage. The assignment of taxonomic rank to a peloric, completely cleistogamous orchid, is discussed. Comparison between G. takeshimensis var. shirataniensis and other taxa of Gastrodia revealed that G. qingyunshanensis is conspecific with G. clausa. The ecological significance of the column appendage in G. takeshimensis var. shirataniensis and G. clausa is also discussed.
