36. Populus X gansuensis C. Wang & H. L. Yang in C. Wang & S. L. Tung, Bull. Bot. Res., Harbin. 2(2): 106. 1982.
二白杨 er bai yang
Trees to more than 20 m tall; trunk straight; bark grayish green, smooth, ± russet and shallowly furrowed at base of old trunk; crown long ovoid or narrowly ellipsoid. Branches stout, subwhorled, spreading from trunk at ca. 45° , on male trees at ca. 60° ; sprouts and branchlets angled. Leaves of short branchlets with petiole terete, compressed distally, 3-5 cm; leaf blade broadly ovate or rhombic-ovate, broadest below middle, 5-6 × 4-5 cm, abaxially pale, adaxially green, base rounded or broadly cuneate, margin glandular serrulate, entire near base, apex acuminate. Sprouts and long shoots with leaf blade deltoid or deltoid-ovate, ca. as long as wide, 7-8 cm, base truncate or subrounded, margin obtusely serrate near base. Male catkin slender, 6-8 cm. Male flower: stamens 8-13; filaments ca. 3 × as long as anthers. Female catkin 5-6 cm, to 12 cm in fruit; rachis glabrous; bracts flabelliform, laciniate. Female flower: ovary glabrous. Capsule long ovoid, 4-5 mm, 2-valved; stipe ca. 0.5 mm. Fl. Apr, fr. May.
* Along irrigation canals and ditches, roadsides. Gansu (Jiuquan Xian, Wuwei Xian, Zhangye Xian); planted in Nei Mongol
Probably a natural hybrid between Populus nigra var. thevestina and P. simonii. Similar to the latter but bark grayish green; crown long ovoid or narrowly ellipsoid, stratified; branches subwhorled; leaf blade of long shoots deltoid, those of shorter branchlets broadest below middle; petioles compressed distally; flowering catkin longer.