Poplars, Aspens, and Cotton- Woods. 6 1 1 



and with a droopiug spray the resemblance to a willow is very 

 striking, as seen on the Platte Eiver or Denver Colorado. Nuttall 

 considered this a good species, and says it becomes a noble tree on 

 the western coast. 



4. Populus tricocarpa (Torrey), is another western form, found in 

 Truchee Valley, Nevada, and elsewhere in the heart of the liocky 

 Mountains, as well as on the Santa Clara Eiver, California.* 



5. Popidus nigra (Linn.), European Poplar, was not recognised by the 

 Michaux and Pursk, though they found a form of it growing in New 

 York City, and on the Hudson river near Albany, which was described 

 as the P. Hudsonica by Michaux, and by Pursk as P. hetulifolia. 

 There is now no doubt about its having been introduced from Europe, 

 where it grows to a large size, and with P. alba is much used along 

 the banks of the Danube in reclaiming low and overflowed lands. 

 The thickets arrest the debris of floods, and furnish abundant material 

 for the fascines used in the weir-drovs and levers placed along the 

 river for the improvement of the navigation of that noble stream. 



10. Populus dilatata (Alton), the Lombardy, or Italian Poplar, 

 is no longer looked upon as a species in this country, but merely as a 

 variety or sport from the P. nigra. This plant is extensively grown 

 as an avenue-tree along the highways of Southern Europe, where it 

 appears to be a great favourite, notwithstanding its formal habit. It 

 does not appear even there to be valued for its timber, and is never 

 seen in forest plantations. 



The Lombardy was very early introduced into this country. In 1784, 

 it was planted by Wm. Hamilton, Esq., on the site of the Centennial 

 Exhibition {vide Watson's Annals of Philadelphia), and extensively 

 planted elsewhere, particularly in the streets of towns and cities. In 

 the eastern States very large trees may yet be seen in good condition, 

 but in the western States, especally in Northern Illinois and Wis- 

 consin, it lias been largely planted in fence rows and wind-breaks with 

 fine effect. In our soil, however, the tree does not promise to be long- 

 lived. The plants in this country are all staminate or males, and have 

 been multiplied by cuttings. How is it in Europe ? •!- 



Aspens. 



The aspens, or abeles, form a distinct group ; they are usually 

 smaller trees, as we see them here, especially the native species. 



* North Am. Sylva, Michaux and Nuttall. Vol. iv. of Nuttall, vol.i., p. 64. 

 Philadelphia Edition. 



t This question is already answered by my friend and jury colleague at Vienna, 

 Giovanni Carlo Sismoris, who says this Poplar, which he also calls the Cypress or 

 pyramidal, and P. Italica Dur., is considered only a variety of P. nigra. No firmer plants 

 are known. He adds that it is much cultivated in Lombardy, and particularly along the 

 Po. In evidence of its antiquity he quotes Ovid.— Manuale d'Arte Forestale, 

 1872, p. 137.— J. A. W. 



