A' 



TREES AND SHRUBS. 



POPULUS SARGEOTII, Dode. 



Populus Sargentii, Dode, Extr. Monogr. Ined. Populus, 40 (1905). — Britton & Sbafer, N. 



Am. Trees, 178, f. 136. 

 Populus angulata, Porter & Coulter, Fl. Colorado; HayderCs Surv. Misc. Pub. No 4 129 



(not Aiton) (1874). 

 'opulus deltoidea, Sargent, Silva N. Am. ix. 179 (in so far as relates to the Rocky Moun- 

 "~ not Marshall) (1896). 

 Populus deltoides occidentals, Rydberg, ex Britton, Man. ed. 2, 310 (1905). 

 Populus occidentals, Rydberg, Bull. C. Agric. Exper. Stat. Colorado, 91 (Fl. Colorado) 



(1906). — Nelson, Coulter, Man. Rocky Mt. Bot. ed. 2, 128. 



Leaves often broader than long, ovate, abruptly narrowed into long slender acuminate entire 

 points, or rarely rounded at the apex, truncate or slightly cordate at the base, coarsely crenately 

 toothed ; when they unfold slightly villose above and tomentose on the margins, soon becoming 

 glabrous, light green and very lustrous, from 7 to 8 centimetres long and from 9 to 10 centimetres 

 wide, with thin midribs, slender primary veins and reticulate veinlets, occasionally furnished on 

 the upper side at the insertion of the petioles with one or two small glands ; petioles slender, later- 

 ally compressed, glabrous, from 6 to 9 centimetres in length. Flowers in the axils of scarious light 

 brown scales fimbriately divided at the apex, the staminate in short-stalked glabrous aments from 

 5 to 6 centimetres long, the pistillate becoming from 1 to 1.2 decimetres in length at maturity; 

 disk of the staminate flower broad, oblique, slightly thickened on the margins ; stamens twenty or 

 more, with short filaments and yellow anthers ; disk of the pistillate flower cup-shaped ; ovary sub- 

 globose, crowned with three or four sessile dilated or laciniately lobed stigmas. Fruit oblong-ovate, 

 gradually or abruptly narrowed to the blunt apex, about 1 centimetre long and 3 or 4 times longer 

 than the pedicel ; seeds oblong-obovate, rounded at the apex, about 1.5 millimetres in length. 



A tree, from 20 to 30 metres high, with a trunk covered with thick pale bark divided by deep 

 furrows into broad ridges, large, erect and spreading branches forming a broad open head, and stout 

 glabrous light yellow branchlets conspicuously roughened by the elevated scars of fallen leaves. 

 Winter-buds ovate, acute, their scales light orange-brown and puberulous. 



This is the common Cottonwood of riverbanks in the eastern foothill region of the Rocky Mountains from Saskatche- 

 wan to New Mexico, ranging east to Dakota, Nebraska, western Kansas (Atwood, Rawlins County, in Herb. Mo. Bot. 

 Gard.) and to western Texas. 1 It is very common and the only broad-leaved Cottonwood in central Colorado, where it is 

 much planted as a shade tree. Long confounded with Populus deltoidea Marshall, the Cottonwood of the eastern states, 

 this tree was first distinguished by Professor William Trelease in his unpublished study of the North American Poplars 

 as var. intermedia in Herb. As he pointed out, it can be distinguished from the eastern tree by the pale yellow color 

 of the branches, by the pubescent buds, by the much shorter pedicel of the female flower and fruit, and by the larger and 

 fewer teeth of the leaves. 2 



1 The eastern range of this tree and the western range of Populus deltoidea have n 

 2 NOTES ON POPULUS. 



There is a Poplar cultivated in Germany as Populus angviata which has the scale! 

 divided, at the apex, and leaves similar to those of Populus deltoidea (see C. K. Scl 

 f . 3, q-r. A careful examination of the Poplars growing in many parts of the east 

 character. The tree which is sometimes found in English collections as Populus ang 



