BETULA 257 



narrower and longer (being i^ to i ins. long, ^ to ^ in. wide), and the central 

 lobe of the scale more tapered. This variety thrives better in cultivation 

 through starting later into growth, and makes a clean-grown, handsome 

 birch one of the most striking of the white-stemmed group. 



B. FONTINALIS, Sargent. WESTERN BLACK BIRCH. 



A shrub up to 15 or 20 ft. high, occasionally a tree twice, as high, of elegant 

 form ; bark almost black, not peeling ; young shoots resinous, warted. Leaves 

 glandular, broadly ovate, rounded or slightly heart-shaped at the base, pointed, 

 double-toothed ; I to 2 ins. long, | to \\ ins. wide ; dark dull green, slightly 

 hairy above ; paler and soon almost smooth beneath ; veins in six or seven 

 pairs ; stalks \ to \ in. long, at first somewhat hairy, then smooth. Male 

 catkins up to 2 ins. long. Fruiting catkins i to \\ ins. long, the lobes of the 

 scales about equal in size, slightly downy or smooth. 



Native of Western N. America; introduced in 1897 to Kew, where it thrives 

 very well, and promises to make a graceful small tree. It belongs to the 

 alaskana and kenaica group, but is distinguished by the bark not separating 

 into layers, and in being almost black. The very resinous young twigs and 

 glandular young leaves also mark it. 



B. GLANDULOSA, Michaux. 



A shrub procumbent at high elevations, rarely more than 4 ft. high any- 

 where ; young shoots not downy, but covered with glands. Leaves obovate to 

 roundish or kidney-shaped, usually \ to f in. (sometimes over i in.) long, green 

 and smooth both sides, conspicuously round-toothed ; stalks up to j in. long. 

 Fruiting catkins erect, ^ to f in. long. 



Native of N. America, where it reaches across the continent at high 

 latitudes and high altitudes ; also of Greenland. It is closely allied to, and 

 can only be confused with, B. nana (?.?/.), but is abundantly distinct in its 

 glandular- warted branchlets and longer-stalked leaves. It occupies similar 

 moist positions in nature, and may be planted in similar positions in gardens. 



B. HUMILIS, Schrank. SHRUBBY BIRCH. 



A shrub 2 to 9 ft. high, young shoots hairy and glandular-warty. Leaves 

 ovate, oval, or obovate, \ to i\ ins. long, mostly tapered (sometimes rounded) 

 at the base, pointed, irregularly and rather coarsely toothed (teeth triangular 

 but often bluntish) ; both surfaces smooth and green ; veins in four or five 

 pairs ; stalk in. or less long. Fruiting catkins to f in. long ; scales with 

 minute hairs on the margin, deeply three-lobed, the middle lobe usually thinner 

 and larger than the side ones. 



Native of high latitudes in Europe and Asia, or of high altitudes in more 

 southerly regions. This species and B. FRUTICOSA, Pallas, are very closely 

 allied, and have often been united. The leaves of B. fruticosa are more 

 tapered towards the apex, have usually five or six pairs of veins, and the 

 toothing is finer, sharper, and more regular ; the wings of the seed are also 

 comparatively broader than in humilis. It is a native of N.E. Europe and 

 Siberia, inhabiting boggy places. 



B. JACQUEMONTII, Spach. 

 (B. utilis var. Jacquemontii, Regel.} 



This tree, a native of the Himalaya, is usually associated with B. utilis, but 

 is so distinct in various characters that it will be convenient to regard it as a 



