Plants to 30 m. Branchlets, leaf blades, and petioles glabrous or glabrate to densely hairy, hairs whitish. Neoformed leaves: blade broadly triangular-ovate, usually about as wide as long, rarely wider, base truncate or cordate, apex short-acuminate. Capsules (6-)7.5-11 mm. Flowering Feb-May; fruiting Mar-Jun. Floodplains, canyons, springs, other moist places; (-60-)0-1500 (-2200) m; Ariz., Calif., Idaho, Nev., N.Mex., Utah; Mexico (Baja California, Baja California Sur, Sonora). Subspecies fremontii is the common cottonwood of southwestern North America west of the Continental Divide. It intergrades with subsp. mesetae along a line from southeastern Arizona south along the border between Chihuahua and Sonora.
LEAVES: broadly triangular-ovate, usually about as wide as long. NOTES: See also parent taxon. Floodplains, canyons, springs and other moist places: all cos. except Apache; 8-2200 m (25-7300 ft); Feb-Apr (fr. Mar-May); w of the continental divide, n CA and n UT to Baja C. Sur and c Son., Mex. REFERENCES: Eckenwalder, James E. 1992. Salicaceae. Ariz.-Nev. Acad. Sci. 26(1)2.