Japan Flora: Shrub, the branches with rather flattened prickles, the flowering branchlets elongate, slightly prickly and pubescent; leaflets 3, acuminate to very acute, sparingly appressed-pnbescent to glabrous and green above, with appressed-pubescence on nerves and whitish (but later becoming green) tomentose be- neath, irregularly doubly acute-toothed, the terminal leaflet slighdy larger, rhombic-oblong to ovate, 5-10 cm. long, 2.5-5 cm. wide, obtuse to nearly rounded at base, the petioles thinly pubescent and prickly; inflorescence terminal, few-flowered, the pedicels short; calyx thinly pubescent outside, the lobes nar- rowly ovate, abruptly caudate-acuminate, densely puberulent inside and on the margin; petals pinkish, obovate, 5-7 mm. long; carpels puberulent. May-June.
Honshu (Iwaki and Shinano Prov. and Chugoku Distr.), Kyushu; rare.