Betula.] LXX. BETULACEiE. 459 



A moderate-sized tree, the current year's branchlets pubescent ; root- 

 suckers and luxuriant shoots soft-tomentose. Leaves ovate or ovate-lanceo- 

 late, acuminate, unequally serrate, teeth cuspidate, often aristate, more or 

 less pubescent, sometimes soft-tomentose beneath when young, glabrous and 

 often shining when full-grown, with scattered hairs on the under side along 

 midrib, numerous brown red or black resinous dots on the under side ; 

 blade 3-6 in., petiole J in. long; main lateral nerves 8-12 pair. Catkins 

 fasciculate, short-pedunculate, 3-4 in. long, slender while in flower, J in. 

 diam. while in fruit. Bracts of male catkin subsessile, with 3 tetrandrous 

 flowers on the midrib ; perianth of 4 hairy linear leaves ; anthers hairy, cells 

 distinct. Bracts of female catkin lanceolate at the base, with 2 obtuse or 

 acute teeth or short lobes, as well as ovaries and styles hairy with long 

 hairs. Wings much broader than fruit, and broader than the membran- 

 ous bract of the fruit. 



Himalaya, generally in the outer ranges, extending west to the Sutlej basin, 

 commonly between 5000 and 10,000 ft. Kasia hills 3000-5000 ft. In shady 

 mixed forests, in valleys near streams, mostly singly, not gregarious. Fl. Nov., 

 Dec. ; fr. April, May. Attains 50-60 ft., trunk short, 6 ft. girth and more, 

 branchlets somewhat drooping. Wood whitish, there is some doubt regarding 

 its qualities : Wallich, PI. As. Rar. ii. p. 7, states that it is hard and greatly 

 esteemed by the inhabitants of Nepal, and is employed for all purposes where 

 strength and durability are required. The bark peels off in thick rolls, the 

 lenticels are shorter than in B. Bhojpattra, elliptic or elliptic-oblong. 



Betula alba, Linn. ; Hook. Stud. Fl. 346 Birch ; Birke, German ; Bouleau, 

 French the most important of the numerous species and varieties of this genus 

 in Europe, has long-petioled rhomboid or ovate leaves, solitary female catkins, 

 the fruiting bracts with a cuneate base and a broad 3-lobed apex, wings twice or 

 nearly thrice the breadth of fruit. The wood is yellowish- or reddish- white, 

 with numerous fine medullary rays, and numerous fine, uniformly distributed 

 pores. No heartwood. Weight 32-48 lb. Excellent fuel. Used for carving, 

 furniture, and agricultural implements ; in the Highlands of Scotland, and in 

 North Scandinavia also, for building and a variety of other purposes. The 

 bark is used on roofs under a layer of earth like the Himalayan Birch, and is 

 said to be imperishable. Baskets, boxes, mats, and cordage are made of it 

 in Lapland. 



B. papyracea, Willd., the Paper or Canoe Birch, is a most useful large tree 

 in Canada and the Northern United States. The bark splits into fine paper-like 

 layers, is used as paper, for thatching, and ornaments are made of it. But its 

 principal use is to make the light portable canoes used on the lakes and rivers 

 of Canada. In spring the bark is detached for this purpose in plates 10-12 ft. 

 long and 33 in. broad, which are stitched together with fibrous roots of the white 

 Spruce {Abies alba, Michaux). Kegel classes this Birch as a sub-species under 

 B. alba. 



2. ALNUS, Tournef. 



Deciduous, rarely evergreen trees, with dentate, sometimes entire leaves. 

 Male fl. : either tetrandrous, with 4-lobed perianth, or 6-12 anthers inserted 

 on the stalk of the bract, in the axils of membranous scales ; anther-cells 

 connate, rarely distinct. Female fl. : 2 in the axil of each bract ; bracts 



