Japan Flora: Shrub; young branches slightly striate, glabrous or sparingly pubescent; leaves obovate to broadly obovate or orbicular- ovate, 15-50 mm. long, 10-40 mm. wide, rounded to obtuse at apex, usually broadly cuneate, sometimes rounded or truncate at base, toothed except near base, pale green to slightly glau­cous beneath, the nerves pinnate, the petioles glabrous, 1-3 mm. long; inflorescence terminal, many-flowered, glabrous or with thin rather long pubescence while young; flowers white, 5-8 nun. across; calyx-teeth deltoid, refiexed in fruit; petals ovate-orbicular, shorter than the stamens; nectaries prominent; fruiting carpels glabrous or slightly pilose within. July-Aug. High mountains. 

Hokkaido, Honshu (n. and centr. distr.); rather common. e. Siberia, Sakhalin, and Kuriles.

var. aemiliana (C. K. Schn.) Koidz. Smaller in all parts; young branches usu< ally more or less short-pubescent; leaves broad, rounded at base, 7-15 mm. long, 8-18 mm. wide, the veinlets impressed above; inflorescence smaller, usually short-pubescent; flowers 3-5 mm. across. July-Aug. High mountains; Hokkaido. Kuriles and Kamchatka.

f. glabra (Hara) Ohwi. Plant glabrous.