Ohwi 1985 Flora of Japan

It has a spindle-shaped tuber underground and produces several leaves on a stem that is 15-25cm tall. The lower 1-2 leaves on the stem are linear-lanceolate and about 8-13cm long, while the upper leaves are about 1.5cm long. The inflorescence is terminal and bears 6-20 yellow-green flowers that are about 7-8mm in diameter. The lip is about 4-5mm long with a spur that is 4-10mm long at the base. This is a typical streamside plant that grows on wet rocks in the middle reaches of rivers that are prone to flooding. It is a rare species.

 

Only a few to several individuals were confirmed in each of the two surveyed areas. In one of the areas, the population decreased by 1% due to the impact of dam construction [CR].