188 PBACTICAL FOEESTET, 



and southward to Florida, but most abundant in the Mississippi 

 Valley. . This species has been extensively planted on the prair- 

 ies, and is still highly recommended as a forest tree, but its 

 merits consist mainly in the facility with which it is propagat- 

 ed, and rapidity of its growth, the wood being very inferior, 

 oven for fuel, to some of the other species of this genus. There 

 is a handsome golden-leaved variety of this species, also a weep- 

 ing variety, both handsome little trees. 



P. tremnloides, Michx. — Quaking Asp, American Aspen. — 

 Leaves roundish, heart-shaped, with a sharp point, and some- 

 what regular teeth, smooth on both sides, with downy margins. 

 The leaf -stalks long and slender, slightly flattened on the sides, 

 which probably accounts for the constant ti-embling of the 

 leaves, when there is the slightest breeze. A common and 

 well-known tree, both in forests and under cultivation. A 

 widely distributed species, extending entirely across the Con- 

 tinent, through British America to the Pacific, extending north- 

 ward to the Arctic Ocean. Usually in dense groups on moist 

 soils, on high elevations in our mountain ranges. I have found 

 large groves of this species in the Rocky Mountains at an 

 elevation of ten thousand feet. A medium-sized tree, fifty to 

 seventy-five feet, with stem twelve to twenty-four inches in 

 diameter. Bark smooth, hard, and thin, whitish on the out- 

 side, yellow within, quite brittle. Wood white, soft, but of 

 a firm texture, somewhat resembling that of the White Birch, 

 makes good fuel, and a Quacking Asp log will hold fire longer 

 than any other kind of wood I ever tried while camping in the 

 Kooky Mountain regions. The Indians are well acquainted 

 with this property of the Quacking Asp, and in moving their 

 camps, they use a brand or coals of this tree for taking fire 

 from the old to the new. It is also a favorite tree with the 

 beavers for building their dams. 



P. tricbocarpa, Torr. and Gray. — California Balsam Poplar. — 

 Leaves heart-shaped, or ovate to lanceolate, scalloped with 

 rounded teeth, two to four inches long ; stalks an inch or two 

 long ; fertile catkins five or six inches long. Seeds nearly 

 white. A large tree in California, from San Diego northward 

 to British Columbia. In Washington Territory; it is said to 

 grow nearly one hundred feet high, with stem three to six feet 

 in diameter. In low valleys and canyons near streams. 



