7 6 Trees 



and the leaves, which grow on long stalks, are egg-shaped, 

 finely toothed, dark green on the top and quite pale beneath. 

 The catkins are slender. 



Populus aciiminata, or Cottonwood, is a much smaller 

 tree than the preceding species. It has stout spreading as- 

 cending branches forming a rounded head, very pointed 

 leaves which are toothed except near the apex and base, and 

 pale grey-brown bark divided into broad flat ridges. The 

 bark on the young stems and the branches is smooth and 

 nearly white. 



BLACK BIRCH 



Betula fontinalis. -Birch Family 



A tree with smooth bronze bark. Leaves: broadly ovate, acute, 

 sharply serrate except at the rounded subcordate and often unequal base. 

 Flowers: staminate aments clustered with light brown scales, pistillate 

 aments short-stalked, with ovate acute green scales. Fruit: strobiles 

 cylindrical, puberulous, erect or pendulous on slender stalks. 



The Black Birch is a small tree with slender spreading 

 pendulous branches and lustrous copper or bronze bark. 

 The leaves are broad, and pointed at the apex, pale green 

 above, and yellowish with minute glandular dots below, 

 their short stems often slightly reddened, and they turn com- 

 pletely yellow in the autumn before falling. 



Betula alba var. papyrifera, or Paper Birch, is a large 

 forest tree, with outer lustrous white bark peeling off in 

 thin layers, and disclosing the inner orange surface. The 

 leaves are ovate, very pointed, also coarsely double-toothed 

 all round, and rounded at the base. 



Betula glandulosa, or Dwarf Birch, is a small shrub grow- 

 ing from one to five feet high, or procumbent at high alti- 

 tudes, with glandular, warty twigs, and rounded leaves, 

 bluntly toothed. 



