Japan Flora: Small deciduous tree with rather spreading, stout spines, the young branches glabrous or slightly pubescent, becoming dark purple in age; leaves mem­branous, dull, ovate or broadly so, 5-10 cm. long, 3.5-5 cm. wide, acute, broadly cuneate at base, slightly pubescent, shal­lowly lobed to incised, irregularly and acutely toothed, the petioles 1-3 cm. long, loosely pubescent on the upper side; in­florescence rather many-flowered, glabrous or slightly pubes­cent; flowers white, 10-15 mm. across; calyx-teeth narrowly ovate-lanceolate, subacuminate, reflexed; stamens rather long; styles 5；May-June.

Hokkaido, Honshu (Sugadaira in Shinano). Sakhalin.