64 SPRING FLOWERS. 



(82) Betula. Birch. 



B. alba : tree ; leaves deciduous^ ovate-deltoid, varying to 

 broadly cordate, and with a rliomboidal tendency, acute, un- 

 equally serrated, glabrous, often with resinous spots; male 

 catkins cylindrical, drooping, 1-2 inches long, females shorter 

 and more compact. — Woods. Fl. March, April. 



The Common Birch, B. glutinosa, and the White Birch, B. 

 alba, are two slightly different forms : the first having the 

 fruits broadly obovate, and the lateral lobes of the 3-lobed 

 scales of the female catkins ascending ; the second having the 

 fruits obovate-eUiptical, and the lobes falcate reflexed. 



B. nana : shrub ; leaves deciduous, small, nearly orbicular, 

 crenate, not pointed ; catkins small, oblong, erect. — Spongy 

 Bogs. Fl. May. 



(83) Salix. Willow. 



* Male and female cathins on short leafy shoots. 



S. pentandra : small tree ; leaves thick, smooth, shining, 

 deciduous, broadly lanceolate or ovate, pointed, finely toothed ; 

 catkins cylindrical, loose ; stamens about five, sometimes more. 

 — Bay Willow. — River-sides. Fl. May, June. 



S. fragilis : tree ; leaves deciduous, ovate-lanceolate, pointed, 

 smooth, serrated throughout; catkins long, loose; flowers 

 large ; stamens two ; capsules stalked. — Crack Willow. — 

 Marshy ground. Fl. April, May. 



S. alba : tree ; leaves deciduous, ashy-grey, silky on both 

 sides, elliptic -lanceolate, pointed, serrated ; catkins loose, 

 cylindrical; stamens two; capsules nearly sessile. — Moist 

 woods. Fl. May. 



S. triandra: small tree; leaves deciduous, linear-oblong, 



