Distribution. Banks of mountain streams; southwestern California (Mill Creek, above Forest Home, San Bernardino Mountains) and southern and central Arizona; widely distributed through northern Mexico (var. Jonesii Sarg.); well distinguished from the other Cottonwoods of the United States by its small fruit.
Often planted as a street tree in the towns of southern Arizona.
10. [Populus texana] Sarg.
Leaves thin, glabrous, broadly ovate, gradually narrowed, long-pointed and acuminate at apex, truncate at base, coarsely crenately serrate below the middle, entire above, 3′—3¼′ long and 2¼′—2½′ wide; petioles slender, compressed, 1½′—2½′ in length. Flowers not seen. Fruit: aments slender, glabrous, 2½′—3′ long; fruit oblong-ovoid, acute, deeply pitted, glabrous, thin-walled, 3-valved, ⅓′ in length; disk slightly lobed; pedicel slender, 1/16′—⅛′ in length; seeds ovoid, acuminate, 1/16′ long.
A tree up to 60° high, with a trunk sometimes 3° in diameter, stout more or less pendulous branches and stout glabrous pale yellow-brown branchlets. Winter-buds acuminate, glabrous.
In cañons and along the streams of northwestern Texas, where it appears to be the only Cottonwood.
11. [Populus McDougallii] Rose.
Leaves broadly ovate, abruptly short-pointed or acute at apex, broadly or acutely cuneate or truncate, or on vigorous shoots rarely slightly cordate at base, finely or often coarsely crenately serrate, bluish green, thin, pubescent on the under sides of the midrib and primary veins early in the season, otherwise glabrous, 1½′—3′ long and broad, with slender midribs and veins; petioles slender, slightly compressed, pubescent early in the season, becoming glabrous, 1½′—2′ in length. Flowers not seen. Fruit: aments glabrous, short-stalked, 2′—2½′ long; fruit ovoid and acute at apex to ellipsoidal and acute or acuminate at ends, glabrous, slightly pitted, thin-walled, 3-valved, 5/12′—½′ long; disk not more than ⅛′ in diameter; pedicels glabrous, ⅛′—⅕′ in length; seeds oblong-ovoid, acuminate, ⅛′ long.