Information not available
- NW Washington southward to SW California
- SW California southeastward to W Texas
- W Texas northwestward through S New Mexico
- W Utah and Idaho to NW Washington
Arroyo Willow is a large shrub or small tree found alongside streams and arroyos in the western and southwestern regions of the US and may occur from sea level to nearly 7500 feet in elevation. It may get to be as tall as 30 feet but it usually reaches only a fraction of this height. The leaves, up to about 5 inches long, are less than an inch wide and tend to be widest at or beyond the middle portion. While the upper surfaces of the leaves are dark green and smooth above, the undersides are whitish and sometimes fuzzy. Male and female flowers form in the spring, but on separate trees. Both kinds of flowers are in the form of catkins; pollination is apparently achieved mostly by insects, and the female flowers, after fertilization, ripen and release their cottony seeds to the wind.