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cylindrical, on long, slender, minutely pubescent, glandular stalks; scales long-stalked, veined, puberulous, ciliate, with the triangular central lobe slightly longer than the broad, rounded, recurved, lateral lobes ; nutlets with rather broad wings.

This variety! is distinct in the larger number of nerves in the narrower, longer, slightly pubescent leaves, which are simply serrate in margin ; and in the characters of the fruit-scales. The bark of cultivated trees is more like that of B. Ermani than the common birch, as it is uniformly white in colour, with raised whitish lenticels, and scales off in transverse shreds. According to Sargent,” it is a slender tree, attaining about 80 feet in height in Yezo.

There are three trees of this variety in Kew Gardens, about 20 to 25 feet in height, which were raised from Japanese seed sent by Sargent in 1891 under the erroneous name B. ulmifolia. A similar tree,® 25 feet high, cultivated at Kew as B. alba, var. latifolia, was obtained from Madrid in 1887. These trees are narrowly pyramidal in habit, and very ornamental on account of their beautiful white bark; and appear to be fast in growth and very thriving.

4. Several varieties have arisen in cultivation, of which the most noteworthy are:—

Var. Youngi, Schneider, Young’s weeping birch; and var. elegans, Schelle, Bonamy’s* weeping birch. Both these forms have long, slender, pendulous branchlets ; and are usually grafted on stems 6 to 8 feet high, when they assume the habit of the weeping sophora. A fine specimen is growing in Smith’s nursery at Worcester.

Var. fastigiata, Schelle, is characterised by its upright branches, the tree resembling in its appearance a Lombardy poplar. According to a writer in Woods and Forests, this variety retains its foliage later in autumn than any other form of the silver or common birch.

Var. purpurea.” Leaves purple, resembling in colour those of the purple beech, valuable for ornamental planting.

This species is widely distributed in Europe, and in northern and eastern Asia. The northern limit, beginning in Scotland, crosses Norway in lat. 64°, Sweden in lat. 65°, and ascends in Russian Lapland to Lake Ruanjärvi; and thence, crossing Lake Onega, passes through the province of Vologda to Siberia, where its exact distribution has not been made out. In eastern Asia, var. japonica is met with in Manchuria, Saghalien, and Japan. The type occurs in the mountains of north China, and was found near Lake Kokonor (lat. 37° 50’) by Przewalski; and it appears to be the common birch in the Altai and Ural mountains. It is not found in Persia or Afghanistan, but occurs on the higher mountains of the Caucasus and in Armenia and Asia Minor. In Europe the southern limit extends from the

i The Japanese name for this variety is Shira-Kamba.

2 Forest Flora of Japan, 61 (1894).

3 This tree has broadly ovate leaves, subcordate or rounded at the base, and larger than those of the trees raised from Japanese seed, sent by Sargent; but in other respects is identical, and is probably also of Japanese origin.

4 This originated in Bonamy’s nursery at Toulouse, and is usually known in gardens as B. alba pendula elegans. Cf. Rev. Hort., 1869, p. 135, fig. 33, and Gard. Chron., 1869, p. 1278.

5 Probably identical with var. atrosanguinea, stated by Schübeler to have originated in France, and to be growing in the Botanic Garden at Christiana.—(H.J.E.)