Variations 
var. hondoense
This variable shrub can have a solitary erect stem or multiple creeping stems that self layer. It is similar to the species differing in having thinner pale green leaves with appressed tomentum on the underside.

var. pentamerum
This shrub grows to 2 m (6 ft) tall with oblanceolate leaves 250 mm (9¾ in) long and has pale brown tomentum on the underside. It produces 5-petalled flowers that are up to 40 mm (1⅝ in) wide during late spring to early summer. It naturally occurs at high altitude woodlands in the mountains of Honshu.

var. yakushimanum
This shrub is found in the high altitude mountains of Kyushu and is similar to the species but has dense tomentose on the underside of the leaves and on the flower pedestals.