BETULA , 255 



As garden trees, the birches are chiefly valued for their striking trunks 

 and graceful branches. The silvery trunks of such species as verrucosa, 

 papyrifera, and Ermani provide some of the most delightful of winter 

 effects. Nor are the darker coloured ones of lutea and Maximowiczii 

 without their charm. The rugged trunks of nigra and davurica always 

 attract attention. On the whole, no birch exceeds our native B. verrucosa 

 in beauty, not only in its trunk, but in the singular lightness and delicate 

 grace of its branching also. Most people will agree with the oft-quoted 

 words of Coleridge, that it is 



" most beautiful 

 Of forest trees, the Lady of the Woods." 



The young branches and twigs of many birches have a rich red brown or 

 orange-brown tint, which makes an admirable contrast in winter with such 

 as have white trunks. 



So far as I have seen, the birches thrive best on a deep, well-drained 

 loam, and I do not know that any object to it. But some species, like 

 verrucosa and populifolia, are amongst the best trees for poor, sandy soils ; 

 whilst B. pubescens, nana, glandulosa, pumila, and nigra thrive well with 

 their roots within reach of water. 



Whenever possible the birches should be raised from seed, which 

 most of them develop in plenty. It should be sown on the surface 

 of fine soil, and not buried but simply pressed down. An old and good 

 plan when the seed is sown out-of-doors is to cover it thinly until it 

 germinates with a thin layer of brushwood, which gives shade and shelter 

 and protects it from interference by birds, etc. 



The common birches are attacked by a gall-producing insect, Phytoptus 

 ritdis, which causes an abnormal swelling of the leaf-buds, and distorted, 

 stunted growths. 



Several hybrids have appeared in nature between the various birches, 

 amongst which are : 



lenta x pumila. pubescens x humilis. 



papyrifera x fontinalis. pubescens x nana (see intermedia). 



papyrifera x pumila. pubescens x verrucosa. 



B. ALASKAN A, Sargent. YUKON BIRCH. 



A tree 30 to 40 ft. high, with the young shoots thickly covered with viscid 

 warts, not downy. Leaves triangular-ovate, wedge-shaped or cut straight 

 across at the base (heart-shaped on strong shoots), taper-pointed, i| to 3 ins. 

 long, I to 2 ins. wide ; coarsely and often doubly toothed ; glossy dark 

 green, viscid, and slightly hairy ; stalks J to I in. long, reddish. Fruiting 

 catkins i to 1 1 ins. long ; scales hairy on the margin only, the side-lobes 

 larger, rounder, and broader than the middle one. 



Native of Alaska, especially in the Yukon Valley ; introduced in 1905. 

 A young tree sent to Kew by Prof. Sargent is thriving very well, and promises 

 to make a handsome tree. It is in some respects like B. fontinalis, but 

 differs in its thin, peeling, reddish brown, or dull white bark, and in the 

 broader wing to the seeds. Sargent describes it as the common birch of the 

 Yukon Valley. 



