Betula corylifolia Reg. & Maxim.

A deciduous tree up to 60 or 70 ft high, with a greyish-white bark; young shoots glabrous except for a few hairs when quite young, dark purplish brown, with pale scattered warts. Leaves ovate-elliptical, often inclined to obovate, truncate to widely tapered at the base, pointed, coarsely and triangularly (sometimes doubly) toothed; 11⁄2 to 3 in. long, 1 to 2 in. wide; glabrous above, slightly glaucous and silky-hairy on the midrib and veins beneath; veins in ten to thirteen pairs; stalk 1⁄3 to 5⁄8 in. long, silky-hairy when young. Male catkins slender, about 2 in. long. Female catkins 11⁄2 to 2 in. long, 5⁄8 in. wide, cylindrical; scales deeply three-lobed, the lobes linear and erect, the middle one twice as long as the side ones, silky-hairy especially towards the tip. The seeds have narrow wings.

Native of the main island of Japan. There have been several birches grown in gardens under this name at different times, but most of them wrongly. Yet the true thing is very distinct, especially in the large, triangular, often incurved teeth of the leaves, their rather glaucous under-surface, and the very narrow ciliate lobes of the fruiting scales. Coming from high altitudes, it is very hardy. There is an authentic example at Edinburgh, raised from seed collected by Wilson for the Arnold Arboretum in 1914.