AND U. S. EXPERIMENT STATION. 27 



great a variety of soils and locations as the box elder. It is native 

 along streams, in low, rich land, and when transplanted to ridges it 

 often fails. Of late too, the cottonwood beetle has become a very seri- 

 ous pest, not infrequently killing whole plantations. I am not aware 

 of any effectual way of killing this beetle. The principal value of the 

 cottonwood is in its rapid growth. The timber is about equal to box. 

 elder, neither being good for much save for burning, and they are of 

 only moderate value as fuel. 



THE RUSSIAN POPLARS. A number of poplars trees closely re- 

 sembling the cottonwood have been disseminated over the northwest 

 by the Department of Agriculture and the Iowa Agricultural College. 

 Most of these varieties are known by the common name Russian Pop- 

 lar. Not counting the silver-leaved sorts, but few of which have been 

 distributed, there seems to be only one of the Russians that merits 

 special notice. This is Populus certinensis. This tree is a very rapid 

 grower, and succeeds, like the box elder, on both high and low land, 

 and in almost if not all soils. In habit it is more erect than cotton- 

 wood, growing tall and straight. Its leaf resembles the cottonwood, 

 save that its serrate margin is curved in and out. It has been grown 

 from one year old plants at the station, and thus far only good words 

 can be said of it. The one drawback to its success is the cottonwood 

 beetle, which seems rather to prefer this tree to the cottonwood itself. 

 The wood is in its general nature like cottonwood, but is said to be 

 superior to that tree. It is worthy extensive trial. 



BLACK WILD CHERRY. As regards growth during the present 

 year, I should place this after the ash and elm. In the plantation 

 there is one plat in which ash, elm, birch and wild cherry are alter- 

 nated. The ash rows are uniformly good, though not so high as the 

 elms. The elms are far more uneven in height than the ash, and a 

 few are missing. The cherries seem healthy, but they have not grown 

 as much on the average as the ash, nor is the stand as good as the elm. 

 The variety is "promising, and as no timber is more valuable for special 

 uses, it will repay a little care. 



WHITE OAK. About a hundred trees of this species were placed in 

 the plantation last spring. About half of them lived, but very few did 

 more than grow a tuft of leaves, or a small branch from near the 

 ground. In taking up specimen plants for the fair in September, I 

 found that a good root growth had been made. About seven miles 

 east of the College is a grove of oaks and walnuts, seven years of age, 

 in which the white oaks average six feet in height. As will be seen in 

 the tables, oaks in our seedling grove, two years from the acorn, are 



