978 The Trees of Great Britain and Ireland 



Var. nipponica,' Maximowicz, MSl. Biol. xii. 923 (1888). This differs from the 

 type in the branchlets not being so densely glandular, and in the longer, narrower 

 cones, which are cylindrical, ^ inch long, and 1 inch in diameter. This variety was 

 found by Maximowicz in the Nikko mountains, and is probably the form of the 

 species occurring in the main island of Japan. 



B. Ermani is widely distributed in eastern Asia, occurring in Kamtschatka, 

 Manchuria, Korea, Saghalien, Kurile Isles, and Japan. According to Komarov,' it 

 grows in Manchuria, near the sea-coast, from the river Amur to St. Olga Bay, in 

 the Sichote-Alin mountains, in the north-eastern part of the province of Mukden, 

 and in the Korean main range ; and is a native of mountain forests at elevations 

 between 2000 and 7000 feet. Komarov informs us that it is the largest of the 

 birches, which he found in Manchuria, attaining a height of 60 to 100 feet. 



According to Sargent,^ it is the most common birch in the high mountains of 

 the main island of Japan, where it is scattered through the coniferous forests at 

 4000 to 6000 feet, and is very conspicuous from the white bark of the trunk, and the 

 bright, orange-coloured bark of the principal branches. It appears to be the birch 

 figured and described by Shirasawa,^ as Betula alba, var. communis (not Regel), 

 which he states to be a tree of vigorous growth, attaining 70 feet in height and 

 3 feet in diameter, occurring in the central chain of Honshu, especially at Shimot- 

 suke, in Nikko, Musachi, in Chichibu, and Kiso, in Shinano. At Kiso the bark 

 is used as material for writing on, and for envelopes ; and also for torches, 

 as it contains a considerable amount of resin. Elwes saw a birch, which he believes 

 to be B. Ermani, growing in great abundance in the forest north of Asahigawa, 

 and also on the volcanic cone near Lake Shikotsu, in Hokkaido. Here it seemed 

 to be commoner than, but not so large, a tree as B. Maximowiczii. 



This species was introduced into cultivation through the agency of the 

 St. Petersburg Botanic Garden ; and is not uncommon in gardens both on the 

 Continent and in England, where it is often wrongly named B. ulmifolia, B. corylifolia, 

 etc. At Kew there are small trees, 20 to 25 feet in height, both of the typical 

 form and of var. nipponica. The former* is the first of the birches to come into 

 leaf, the foliage often being fully developed at the end of March ; and, in conse- 

 quence, the trees are usually much injured by spring frosts. The largest tree we 

 have seen of this species is in the arboretum at Westonbirt, and when measured by 

 Elwes in 1908, was 51 feet by 2\ feet. There is a good specimen apparently of 

 the typical form at Benmore, in Argyleshire, which is grafted near the ground, 

 and has yellowish scaly bark like that of B. lutea. In 1907 Elwes found it to be 

 about 40 feet by 3 feet. Var. nipponica is later in leafing, and is not usually injured 

 by frost. Two trees of this variety at Grayswood, Haslemere, are about 30 feet 

 in height. (A. H.) 



» This variety appears to be identical with a specimen in the ICew herbarium collected by Tschonoski on "high 

 mountains not far from Fuji-yama," which is labelled B. Bhojpattra, var. subcordata, Regel, in DC. Prod. xvi. 2, p. 

 177 (is&s). 2 Flora Manshuria, ii. co fioo'?) 



3 Forest Flora o/Japa7i, 62 (lign). 



1 Icon. Essences Forest. Japon, text 42, t. 21 ff. 1-15 (1900). Betula alba, var. communis, Regel, is B. papyHfera 

 an American species, which certainly does not occur wild in Japan. '■ ^j J > 



^ The trees of the typical form were raised from seed sent by the Arnold Arboretum in 1893. 



