The willows are a fairly large genus in the American Southwest, and at some point I'll try to add all the willows to be found in this region. Right now, I'll keep the list to those species I have photos of, which will be a short list for while.
Narrowleaf Willow, Narrow-leaved Willow, Coyote Willow: Salix exigua var. exigua (Synonyms: Salix exigua var. nevadensis, Salix exigua var. stenophylla)