Notes For Reference:-

Species, Varieties, or Forms in the Genus Isodon:

Isodon inflexus / Yamahakka
Isodon inflexus f. leucanthu / Shirobanayamahakka
Isodon japonicus / Hikiokoshi
Isodon longitubus / Akichouji
Isodon longitubus f. albiflora / Shirobanaakichouji
Isodon shikokianus var. intermedius / Takakumahikiokoshi
Isodon shikokiana var. occidentalis / San'inhikiokoshi
Isodon shikokiana var. occidentalis f. albiflorus / Shirobanasan'inhikiokoshi
Isodon trichocarpus / Kurobanahikiokoshi
Isodon umbrosus / Inuyamahakka

Isodon shikokiana var. occidentalis / San'inhikiokoshi サンインヒキオコシ

Isodon shikokiana var. occidentalis is a perennial herb found in broad-leaved forests, such as those dominated by beech trees. Stems grow to 40-80cm in height and have four ridges. Leaves are of opposite phyllotaxis, with bases cuneate, sharp serrations on margins, coarse hairs on both surfaces, adpressed hairs on upper midribs, and erect hairs on the midribs of lower surfaces. The flowers are light purple; the corolla's upper lip is cleft in four and bends upward. Bloom time: August-October.