254 



The Birches 



The branches are slender and usually droop; the young twigs are resinous- 

 glandular, orange-brown, becoming red-brown and shining. The buds are about 

 6 mm. long and resinous. The leaves are ovate, usually broadly so, 2 to 5 cm. long, 

 pointed or bluntish, sharply and sometimes doubly toothed, the base varying 

 from wedge shaped to rounded ; they are hairy beneath along the veins when young, 

 nearly smooth when old, dark green and dull on the upper side, yellow-green be- 

 neath; the leaf-stalks are 7 to 15 mm. long, the stipules ovate, i cm. long or less. 

 The tree flowers in April or May. The staminate catkins are 6 cm. long or less. 

 The ripe pistillate catkins are cylindric, stalked, 2 to 3 cm. long, i cm. thick or 

 less, their scales hairy-fringed with ascending or erect lateral lobes mostly much 

 shorter than the niiddle one; the nut is oval and narrower than its wings. 



9. UTAH BIRCH— Betula utahensis Britton 



The distribution of this birch is, so far as 

 is known, only in the vicinity of Salt Lake 

 City, Utah. 



The young twigs are densely resinous, 

 glandular, greenish brown, becoming bright 

 brown and shining. The young leaves are 

 hairy on both sides, the old ones smooth, 

 except for a few hairs on the veins beneath ; 

 they are ovate to ovate-orbicular, sharply 

 toothed with abruptly tipped teeth, pointed, 5 

 cm.. long or less, and sometimes as wide as 

 long, narrowed or truncate at the base, the 

 upper surface dull green, the under side paler. 

 The tree flowers in April and has clustered 

 staminate catkins 5 cm. long or longer. The 

 ripe pistillate catkins are cylindric, stout, 3 or 

 4 cm. long, more than i cm. thick, and are 

 borne on stalks about 6 mm. long; their scales 

 are nearly as wide as long, finely hairy and 

 hairy-fringed, the lateral lobes obliquely ovate, 



widely spreading, and about as long as the triangular-lanceolate middle one; the 



nut is obovate, 2 mm. long, narrower than its wings. 



Fig. 211. — Utah Birch. 



10. PIPER'S BIRCH — Betula Piperi Britton 



This species inhabits wet soil in eastern Washington and adjacent Idaho. 

 It attains a height of 15 meters and is a slender tree with drooping branches. 



The bark is dark bronze in color, thin, and does not peel off readily. The 

 young twigs are very slender, green and glandular, becoming brown or gray- 



