New natural hybrid in the genus Gastrodia: Gastrodia × nippo-uraiensis (Orchidaceae) from Yakushima Island, Japan

New natural hybrid in the genus Gastrodia: Gastrodia × nippo-uraiensis (Orchidaceae) from Yakushima Island, Japan

We describe a new taxon of Gastrodia (Orchidaceae), G.×nippo-uraiensis from Yakushima Island. Gastrodia×nippo-uraiensis shows similar outer appearances with both G. nipponica and G. uraiensis. It could, however, be easily recognized by the 13–16 mm long perianth tube which is distinctly smaller than G. nipponica (Honda) Tuyama and distinctly larger than G. uraiensis T.C. Hsu & C.M. Kuo. In addition, G. nippo-uraiensis bears mixed or intermediate floral morphological characters between G. nipponica and G. uraiensis. Therefore, this taxon can be considered as a natural hybrid between G. nipponica and G. uraiensis. The morphological characteristics and illustrations of the new taxon, G. nipponica and G. uraiensis are provided.