248 WOODY PLANTS OF MASSACHUSETTS. 



tree is of equally rapid growth, and taller and more shapely. 

 It has been extensively introduced in England and France, 

 where it is valued for its beauty and for its wood. Loudon says 

 that the fine poplar avenues in the lower part of the garden of 

 Versailles, are of this species. In England, it is called the Can- 

 ada poplar, in France, cotton wood. 



Dr. Barratt. of Middletown, Conn., has very kindly communi- 

 cated some very interesting and valuable observations, which 

 he has made in reference to this poplar and others of the genus, 

 together with some striking conclusions as to climate, which he 

 has drawn from the times of flowering of several of the trees. 

 I give them nearly in his own words. 



The aments of P. laevigata are encased, during the winter 

 and early spring, in buds with resinous scales. When the 

 aments begin to protrude, these scales expand, nearly in oppo- 

 site directions, and soon fall. This is about April 9th, and by 

 the 18th, they are in full flower. The aments are first of a 

 rose color, and in great abundance, especially on the upper part 

 of the tree. This monarch of the Amentacese then presents a 

 noble and cheering sight ; and is in a high degree ornamental. 

 As soon as the pollen is shed, which is in two days from the 

 time of the full expansion of the flowers, the rich red pollen 

 cells become pale and shriveled, and the sterile aments are soon 

 scattered in the wind. These aments are from four to five 

 inches long, and have from seventy to one hundred stamens 

 resting on each turbinate scale, and of these scales or clusters 

 of stamens, each anient has sixty or eighty. The carpels, or 

 mature ovaries of the fertile aments, are smooth and ovate, and 

 become ripe about the 18th of June, jast two months from the 

 expansion of the flowers. This fact is the more remarkable, as 

 it is just twice the period of the willows. When the carpels of 

 the poplar are fully open, the cotton adhering to the seeds is 

 shed, and gives the appearance of finely carded cotton, profuse- 

 ly spread among the foliage. Hence the name cotton tree, and 

 we have thus this southern material produced in Massachusetts 

 by a forest tree. 



The other poplars take nearly the same length of time to 

 bring their fruit to perfection. In 1839, which was an aver- 



