Photo courtesy of Mary Ellen (Mel) Harte, bugwood.org
Salix exigua Nutt.
Scientific Name Synonyms:
Life Span: Perennial
Growth Characteristics: Coyote Willow usually forms a thicket with its long, slender stems, seldom exceeding 15 feet in height, but has been known to reach heights of 26 feet. It reproduces by seed and rhizomes (forming clones). Regeneration may also occur through broken pieces of stems and roots that are transported and deposited by floodwaters that later sprout.
Flowers/Inflorescence: Inflorescences are caterpillar-like catkins, which are long spikes containing many small flowers.
Fruits/Seeds: Seeds are very small, enclosed in a dense tuft of silky white hairs.
Leaves: Long, narrow, and tapered at both ends, with short petioles or no petioles. Margins are usually entire or with a few teeth.
Stems: Twigs are hairy and greenish in color. The twigs are also slender and round with bark that loosens easily. Bark is gray-green to brown, smooth on young stems and roughens into scales or shallow furrows and ridges with age. The wood is light, soft, and weak. It is quite susceptible to decay. Buds are located on twigs above leaf petioles.
Coyote willow is found almost exclusively in riparian habitats, occupying banks of major rivers and smaller streams, lakes and ponds, marshy areas, alluvial terraces, and ditches, at elevations from 2,700 to 8,500 feet. It characteristically forms zones immediately adjacent to the water's edge. Coyote willow may also occur on moist, well-drained benches and bottomlands. It normally does not exist in the understory due to its shade intolerance, and is generally replaced by cottonwoods. It is the dominant willow species at low elevations.
Coyote willow is a pioneering species, one of the first to colonize gravelly and sandy flood deposits. It is also well adapted to continued survival on sites that are regularly flooded.
The seeds of coyote willow have a thin seed coat and germinate soon after being dispersed, usually within 24 hours. Seeds older than 1 week rarely germinate; thus seeds must land on suitable sites quickly if they are to germinate. Fresh alluvium deposited along rivers provides an ideal substrate for establishment. These sites have constant soil moisture and generally have no overstory trees to shade out this light-sensitive species.
Soils: Coyote willow occurs on a wide range of soil textures, but usually occurs on soils derived from alluvial or fluvial parent material of mixed geologic origin.
Associated Species: Sedges, rushes, cottonwoods, water birch.
Uses and Management:
Coyote willow is an important food source for many wildlife species. In the Great Basin it has been reported as a favorite food of beaver. Willows (Salix spp.) in general are a preferred food of moose, and coyote willow occurs in riparian and flood plain habitats that these animals frequent. It also is browsed heavily by elk but is of only slight importance as browse for mule deer. Dense stands provide hiding cover for wildlife but at the same time limit access for livestock.
Coyote willow provides excellent browse and shelter for domestic animals as well as wildlife. It is commonly used for soil stabilization and habitat improvement along stream banks. Stands of sandbar willow should be maintained because they help stabilize streambanks and protect them from erosion. Once degradation occurs, streambanks may erode rapidly.
All willows produce salicin, which chemically is closely related to acetylsalicylic acid, commonly known as aspirin. This is probably why Native Americans used various preparations from willows to treat toothache, stomachache, diarrhea, dysentery, and dandruff. Native Americans also used the stems for basketry and bow making, and the bark for tea and fabric making. In many places, during pioneer days, willows were used in the construction of fences, shelters for livestock, and for firewood.