Publication: N. Amer. Sylv. 1: 75. 1842.
selected vouchers: WTU
Notes: FNA7: "Variety exigua forms natural hybrids with var. hindsiana, Salix columbiana, S. interior, and S. melanopsis.
Variety exigua × var. hindsiana was reported by R. D. Dorn (1998). Inasmuch as the two varieties are subtly distinct, hybrids are difficult to recognize.
Variety exigua × Salix interior probably occurs throughout their area of overlap; it is known to me from Alberta and Nebraska, where there are plants with leaves indistinctly toothed and more silky than in S. interior. R. D. Dorn (1998) reported it from Alberta, British Columbia, Colorado, Montana, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming.
Variety exigua × Salix melanopsis is intermediate, with juvenile leaves densely hairy proximally, truncate floral bracts, and prominent stipules (R. D. Dorn 1998)."