Ohwi 1985 Flora of Japan

Japan Red List (2000): The shape of the flower is funnel-shaped with a sakazuki-like form, and the position of the nectary gland is at the base, approximately 1/8 to 1/6 of the way up the flower. The length of the nectary gland is 6-9 mm, similar to that of Kai kobai mo (CR), but it can be distinguished from Hosobana kobai mo (VU) by the presence of protrusions on the flower stalk and the fact that the style does not split much.

It was listed as Data Deficient (DD) on the IUCN Red List, but it is only known from two locations and is being collected for horticulture purposes.   It is classified as Vulnerable (VU).