THE CULTIVATED POPLARS. 223 



strongly angled or grooved and the foliage is much like that of 

 the native cottonwood but darker ; and the growth is more close 

 and erect. The sketch in Fig. 8 distinguishes the leaves perfectly, 

 however : 



P. laurifolia or Certinensis P. monilifera or Cottonwood 

 (upper leaf). Leaves broad-ovate (lower leaf). Leaves triangu- 

 in outline, with a rounded or lar-ovate in outline, with a 

 tapering base and rather short straight or truncate base and a 

 point at the apex ; the margin long point at the apex ; margin 

 rather closely toothed, wavy ; coarsely scallop-toothed, plane; 

 leaf-stalk comparatively short, leaf-stalk long, much flattened 

 only moderately flattened, gland- beneath the blade of the leaf, 

 less at the top ; stipules present and commonly bearing two or 

 and conspicuous. Bud long, three gland-like bodies at its 

 Shoots slightly hairy. top; stipules absent or minute 



(falling early). Bud shorter. 

 Shoots glabrous. 



I imagine that the similarity of the Certinensis poplar and cot- 

 tonwood has been the means of confusing them, for I have pop- 

 lars under the names of P. laurifolia and Riga No. 40, which are 

 cottonwoods. Whether these were really introduced from Russia 

 after having first been introduced there from America, or whether 

 the confusion is a mixing in our own plantations, I am unable to 

 say. The Certinensis poplar is a more rugged tree than the cot- 

 tonwood, with healthier foliage in the presence of leaf-rust, and 

 its wood is said to be valuable. It is now much planted in the 

 Northwest, and deserves to be more widely distributed. 



Its effect in the landscape is considerably unlike that of the 

 cottonwood. Its leaves out stand more horizontally, while those of 

 the cottonwood hang loosely and often vertically and therefore 

 give the tree top a heavier look. The terminal spray of the two 

 is particularly distinguishable in this regard. The leaves of Cer- 

 tinensis upon the strong erect shoots stand almost squarely at 

 right angles with the shoot, and, at some distance, therefore pre- 

 sent only their ruffled edges to the eye, producing a most unique 

 and picturesque effect. But on the whole, at least for the present, 

 I should consider the cottonwood the better tree for ornamental 

 planting in this state. 



