Gastrodia sp.

Family: Orchidaceae
Japanese: タブガワヤツシロラン (椨川八代蘭）) [Yatsushiro Ran]

Incredibly curious plants with . . . odd flowers. This genus is a hotspot for the possibility of new species in Yakushima.

References:
Kenji Suetsugu. First Record of the Mycoheterotrophic Orchid Gastrodia uraiensis (Orchidaceae) from Yakushima Island, Japan. APG : Acta phytotaxonomica et geobotanica 66(3), pp. 193-196, 2015-10-31
Kenji Suetsugu. Range Extensions for Two Mycoheterotrophic Orchids, Gastrodia takeshimensis and G. flexistyloides (Orchidaceae), outside their Type Localit. Acta Phytotax. Geobot. 68 (1): 53–57 (2017)
I am indebted to S. Iwakawa and H. Yamashita for teaching me about these.
米倉浩司・梶田忠 (2003-)　「BG Plants 和名－学名インデックス」（YList），http://ylist.info（ 2019年8月14日）