62 FOREST FLORA OF JAPAN. 



alba is that which botanists call var. Tauschii, and which is distributed from southern Siberia 

 through the Amour country, to Yezo, where it is a slender tree, sometimes eighty feet in 

 height ; it is distinguished by its larger and rather thicker leaves, which are of a deeper and 

 more lustrous green on the upper surface than those of the other forms of the White Birch 

 with which it is associated. It is certainly worth a place in our plantations. The variety 

 verrucosa, well distinguished by the warts which beset the young branches, appears to be 

 confined in Japan to Yezo, where, so far as we were able to observe, it is an exceedingly rare 

 plant. 



In the forests of Yezo, too, we saw, for the first time, Betula Maximowicziana. This is 

 certainly one of the handsomest trees in Japan, and one of the most distinct and beautiful of 

 the Birches ; and its introduction into our plantations was alone well worth the journey to 

 Japan. In Yezo, Betula Maximowicziana is a shapely tree, eighty or ninety feet in height, 

 with a trunk two or three feet in diameter, covered with pale smooth orange-colored bark. 

 Toward the base of old individuals the bark becomes thick and ashy gray, separating into 

 long narrow scales. The branchlets are stout, covered with dark red-brown bark and marked 

 by many pale lenticels. The leaves, however, are the most distinct feature of this tree ; in size 

 they are not equaled by those of any other Birch-tree, and as they flutter on their long 

 slender stalks they offer a spectacle which can be compared with that which is afforded by 

 our Silver-leaved Linden waving its branches before some Hemlock-covered hill of the southern 

 Alleghany Mountains. The leaves of Betula Maximowicziana are broadly ovate, cordate at 

 the base, coarsely and doubly serrate, very thin and membranaceous, dark green and lustrous 

 on the upper surface, pale yellow-green on the lower surface, four to six inches long and four 

 or four and a half inches broad. The flowers and fruit I have not seen. The male catkins 

 in September are an inch and a half long, very slender, with bracts rounded and apiculate at 

 the apex. From the seeds, for which I am indebted to the Forestry officials of Hokkaido, a 

 large number of seedlings of this fine tree have been raised in the Arboretum. Specimens 

 collected in the Nikk5 Mountains by Mayr indicate that it is an inhabitant of Hondo, where, 

 however, we did not see it. From Yezo it ranges northward through Saghalin into Man- 

 churia. The tough thin bark is used by the Ainos for many domestic purposes. 



The most common Birch of the high mountain forests of Hondo is Betula Ermani, a hand- 

 some species now well known in European and American collections, into which it has been 

 introduced through the agency of the St. Petersburg Botanic Garden. In Hondo, where it is 

 found scattered through the coniferous forests, it is common at elevations of from four to six 

 thousand feet above the sea, and is conspicuous from the white bark of the trunk and the 

 bright orange-colored bark of the principal branches. From the different forms of the White 

 Birch this species can be readily distinguished in the herbarium by the long spatulate middle 

 lobe of the bract of the female flower ; in the forest the color of the bark of the branches 

 well distinguishes it. 



On the shores of Lake Yumoto we found a single individual of a black-barked Birch-tree, 

 much hke our American Betula lenta, with the same Cherry-like flavor in the bark of the 

 branchlets. From Betula lenta it differed in its larger, more obtuse and paler winter-buds, in 

 the more prominent midribs and veins of the leaves covered on their lower surface with silky 



