252 NEBRASKA STATE HORTICULTURAL SOCIETY. 



group Caroliniensis is characterized by the very angular branchlets, and 

 contains three species, only two of which interest us here. 



Populus caroliniensis Fouger. — Leaves elliptio-deltoid, truncate and a 

 little heart-shaped at base, very little acuminate at apex; petioles very 

 red. In Dode's cultures only stamiuate trees of this species were grown. 



Populus angulata Michx. — Leaves deltoid or rotund-deltoid, heart- 

 shaped at base, acuminate at apex; petioles red. In Dode's cultures only 

 pistillate trees of this species were grown. 



The group Virginiana is characterized by the less-angled branchlets, 

 and four species. Here we find our common cottoawood, which according 

 to Dode are not of one species, as we have supposed, but of two or more 

 closely related species. 



The foregoing would indicate that the Carolina Poplar should be given 

 a name distinct from the common Cottonwood, and I had reached this 

 conclusion when a new phase of the question came up. For some time 

 those botanists who had studied the Carolina Poplar and the Cottonwood 

 had been in doubt as to whether we were not confusing more than one 

 species of Cottonwood under one name. This has now been decided to be 

 the case, and the eastern Cottonwood is considered to be the tree to 

 which the name Populus deltoides was given by Marshall in 1785. This 

 was for a long time erroneously supposed to be identical with the western 

 Cottonwood which is so abundant along the Missouri river and the 

 streams westward, but the western species is now considered to be dis- 

 tinct, and has been given the appropriate name of Populus occidentalis, 

 or Western Cottonwood. We thus have an eastern and a western species 

 of Cottonwood, as named above. 



Now, what effect will this have on the name of the Carolina Poplar? 

 From what has been said in this paper it is clear that the Carolina 

 Poplar is entirely distinct from our Cottonwood, that is the western 

 species. It is not so clear, however, whether it is distinct from the 

 eastern species, but I have shown above that many botanists have re- 

 garded it as distinct, and even so late a writer as Professor Bailey has 

 considered it to be at least' of a different variety. I cannot decide this 

 matter here, nor need I do so since the eastern Cottonwood is not planted 

 in this region. It is sufficient to show that the Carolina Poplar is cer- 

 tainly of a different species from our western Cottonwood. My present 

 inclination is to treat these trees as follows: 



Eastern Cottonwood — Populus deltoides. Native of eastern North 

 America, extendin.g northward and westward to Quebec and Manitoba, 

 and from thence southward and southeastward. 



Carolina Poplar — Populus angulata. Native of eastern North America, 

 extending southward and westward to Florida and Tennessee, and from 

 thence northward until it meets the preceding species. 



Western Cottonwood — Populus occidentalis. Native of the western 

 region from Saskatchewan and Alberta, .southward to Kansas and New 

 Mexico. The point of the leaf is longer-acuminate, while the base is 



