Japan Flora: Large deciduous shrub to 5 m. high, the branches rather slender, densely white-pubescent while young; leaves in 3’s，terminal on the branchlets, broadly ovate-rhombic, 5-8 cm. long and as wide, abruptly acute, obtuse to acute at base, with scattered long brown hairs on upper side, rusty-brown appressed-pubescent beneath, especially dense on the midrib, the petioles 5-10 mm. long; flowers 2- 4, red, the pedicels 6-13 mm. long, densely appressed rusty-brown pubescent; calyx-teeth minute; corolla 5-6 cm. across; stamens 10; styles white-pubescent at base; capsules narrowly ovoid-cylindric, 1.5-2 cm. long, densely brown-pilose. July. Mountains;

Honshu (lzu Prov.).