- 桧山 智・山手万知子. 1984. 広島県におけるカンアオイ属2種の分布. Hikobia 9: 147-153.
Hiyama, S. & Yamate, M. 1984. The distribution of two species of the genus Heterotropa in Hiroshima Prefecture, S. W. Japan. Hikobia 9: 147-153.
The distribution of Heterotropa hexaloba (F. Maekawa) F. Maekawa and H. aspera (F. Maekawa) F. Maekawa were investigated in Hiroshima Pref., S. W. Japan. These species are easily distinguished from each other by the flower morphology, but the leaves are quite similar. H. hexaloba is distributed in the southwestern part of Hiroshima Pref., and H. aspera is widely found in the other parts. The co-existence of the two species is found at boundary areas.