A tree 60 to 100 ft high in the wild, with a stem 6 to 9 ft in girth; bark nearly black, falling off in thick, rather small plates of irregular shape; young shoots dark brown, warted, at first downy. Leaves ovate, slender-pointed, rounded or widely tapered at the base, finely but irregularly toothed; 11⁄2 to 3 in. long, 1 to 13⁄4 in. wide; veins in nine to eleven pairs, slightly hairy above when young, more persistently so on the veins beneath; stalk 1⁄/6 to 1⁄8 in. long, hairy. Male catkins 11⁄2 to 21⁄2 in. long; female catkins cylindrical, 1 to 11⁄4 in. long, 1⁄8 in. wide, usually solitary, rarely in pairs, stiff and erect at the fruiting state; scales three-lobed, the lobes linear-oblong, pointed, ciliate, the middle one twice as long as the side ones.
Native of Japan, Korea, and Manchuria; named and described by Regel in 1865; introduced to this country in 1914 by Wilson. He says: 'This remarkable birch is rare in Japan and I saw it only on the wooded shores of Lake Chuzenji and in the ascent there from Nikko ... it is a large tree with thick branches.' It may usually be recognised by its blackish bark, erect female catkins, short leaf-stalks and minutely toothed leaves. It is succeeding very well at Kew. The wood is too heavy to float in water.
The present example at Kew, which measures 32 × 2 ft and was planted in 1915, shows very well the striking black bark that characterises this species.
From the Supplement (Vol. V)
The tree at Kew no longer exists but there are young specimens in the birch collection at Wakehurst Place, Sussex, the latest accession being from seeds collected by the Kew expedition to South Korea in 1982, in the Mount Odae National Park, Kangwon province, where the trees seen were about 20 ft high. (B.E. & C. 159).