184 SILVA OF NORTH AMERICA. SALICACEZ. 
red anthers, to the number of sixty or more, are inserted on a broad oblique disk with slightly thickened 
and entire margins. The ovary is ovate or ovate-oblong, glabrous, surmounted by three broad irregu- 
larly crenately lobed stigmas, and inclosed at the base in a broad cup-shaped membranaceous disk which 
is persistent under the fruit. The capsules are ovate, acute or obtuse, slightly pitted, thick-walled, 
three or rarely four-valved, from one third to nearly one half of an inch long, raised on stout stems 
from one twelfth to one sixth of an inch in length, and borne in slender drooping racemes four or 
five inches long. The seeds are nearly an eighth of an inch in length, ovate, acute, light brown, and 
surrounded by a thick tuft of long soft white hairs which entirely cover the mature ament with masses 
of white cotton.’ 
Populus Fremontii, which was long confounded with Populus deltoidea of the eastern states, 1S 
distributed from the valley of the upper Sacramento River southward through western California to 
Lower California,? and eastward to central Nevada, southern Utah, southern Colorado, western Texas, 
and northern Mexico. The Cottonwood lines the banks of streams in all this great territory, and is 
exceedingly abundant in the valleys of central California, where it grows to its largest size, and in all 
the region adjacent to the boundary between the United States and Mexico. 
The wood of Populus Fremontii is light, soft, close-grained but not strong, liable to warp badly 
in drying, and difficult to season ; it is light brown, with thin nearly white sapwood, and contains very 
obscure medullary rays and minute scattered open ducts. The specific gravity of the absolutely dry 
wood is 0.4767, a cubic foot weighing 29.71 pounds. 
The inner bark was made into petticoats by the Indians of some of the tribes of the southwest.’ 
Splendid avenues of Populus Fremontii adorn the streets and squares of the cities of northern 
Mexico, where it has long been planted as a shade-tree.* In the southwestern United States it is now 
cultivated for the same purpose, and for the fuel which pollarded trees produce quickly and abundantly. 
The presence of the Cottonwood indicates the existence of water to the traveler on the arid deserts 
of the Mexican plateau, cheering him with the hope of repose and grateful shade, and enlivening the 
sunburnt plains with a freshness and beauty which are unequaled in early spring before drought has 
parched its leaves or the larve of the Tussock Moth have stripped them from its branches.’ 
1 Sereno Watson distinguished the tree of the territory adjacent 8 Havard, Garden and Forest, iii. 620. 
to the boundary between the United States and Mexico as his va- 4 C. G. Pringle, Garden and Forest, i. 105, f. 
riety Wislizeni by its sharply acuminate leaves cuneate or slightly 5 In southern New Mexico and Arizona and in northern Sonora 
truncate at the base, less dilated staminate disk, shorter pedicels, the leaves are usually entirely devoured by the larve of Hyphantria 
slender pistillate ament, and angled three or four-valved capsules, cunea, Hiibner. The eggs of this moth are deposited on the branches 
but these characters are by no means constant or reliable,and I and the larve are hatched as the leaves are unfolding. During 
cannot separate the Cottonwood of the Mexican plateau and south- May their webs are fully developed and the trees defoliated. After 
ern California from the inhabitant of the valleys of the central part the rains of July and August a second crop of leaves is produced, 
of that state. which fall late in the autumn. 
2 Brandegee, Proc. Cal. Acad. ser. 2, ii. 205 (Pl. Baja Cal.). 
EXPLANATION OF THE PLATE. 
Prate CCCCXCVI. Porutus Fremontn. 
A flowering branch of the staminate tree, natural size. 
A staminate flower with its scale, enlarged. 
A flowering branch of the pistillate tree, natural size. 
. A pistillate flower, enlarged. 
A fruiting branch, natural size. 
ort R Ohh 
. A winter branch, natural size. 
