Japan Flora: Large shrub with pubescent branches; leaves obovate to broadly so, 5-10 cm. long, abruptly acuminate, obsoletely incised and acutely serrulate, rounded or rarely shal-lowly cordate at base, often with a large brown-purple blotch on the center above, glabrous to slightly appressed-pilose on upper side, becoming yellowish brown when dry and loosely ascending-pilose on the nerves beneath, the petioks 1-15 cm. long, pubescent; nuts 1-3 in a cluster, short-conical, 6-8 mm. long, the involucre tubular, 1.5-5 cm. long, narrowed above the nut, shortly lobed or deeply dentate, puberulent and densely bristly-hairy.
Hokkaido, Honshu, Shikoku, Kyushu.
var. brevirostris C. K. Schn. A phase with short in-volucres 1-2 cm. long. Occurs with the typical phase. Korea.
Korea Flora: Deciduous shrub reaching 6m. Winter buds and branchlets: Spathulate, 4-5 scales, terminal and lateral buds similar in size (4-8mm long). New branches with white hairs. Leaf scars small, semi-lunar or triangular. Leaves alternate, ovate-orbicular or spathulate, shortly acuminate apex, rounded or subcordate base, 5-12m × 5-12cm, purple markings on upper surface, fine hairs on lower surface, margins with indistinct lobes and fine serrations. Relatively regular serrations, slender and long or ovoid, leaf tip gradually becoming pointed. Petiole 1-2cm long. Flowers monoecious. Male catkins formed in previous year, 2-5 pendulous at branch tips. Male flowers single per bract with 2 bracteoles, no calyx, 8 stamens. Female catkins winter bud-like with about 10 styles protruding. Fruit and Seeds: Two bracts develop leaf-like, involucral teeth at tip 2-8mm long, not deeply divided and tube narrowing. 20-50mm long, enclosing the fruit. Nut round, 15-29mm in diameter, glabrous.
Sporophyte chromosome number 22. Flowering period: March Fruiting period: September, brown Distribution: Throughout Japan; Jeollanam-do, Gyeongsangnam-do, and Ulleungdo