Growth Form:Shrub; semi-deciduous; profile form willow-like; roots suckering and forming thickets; 1 or more stems; spreading out horizontally and then becoming erect (ascending), stems striped with parallel longitudinal lines (striate) new stems green, turning tan or brownish; stems glabrous, and often with small fine hairs, stems sticky from secretion of yellowish substance (resin), often shows up as resin-varnish.
Leaves: Green; new leaves shiny, alternate on stem; blades linear or elliptic; leaves without stems or supporting stalks (sessile) or with short leaf stems (petiolate) leaf edges or margins not divided and smooth (entire) or finely and evenly serrate; leaves 3 to 6 inches (8-15 cm) long, willow-like, sticky resinous and gland-dotted.
Flowering Season: January to March through October, November and December
Elevation: Up to 5,500 feet (1,600 m)
Habitat Preferences: In moist, riparian and other wetlands, riparian woodlands; springs, drainages, ditches, however, not always found with permanent water, also in dry washes and sandy flood-plains in lower and upper deserts, chaparral vegetation and sage scrub communities and disturbed areas; in Texas found in Valley & foothill waterways to 2,000 feet (600 m).
Recorded Range: Seepwillow is native to the southwestern United States in: AZ, CA, CO, NM, NV, TX and UT. It is also found throughout Baja California and all of Mexico southward to parts of South America.
North America species range map for Baccharis salicifolia:
North American range map courtesy of Virginia Tech, Dept. of Forest Resources & Environmental Conservation
Click image for full size map
U.S. Weed Information: Unknown
Invasive/Noxious Weed Information: Unknown
Wetland Indicator: In North America Baccharis salicifolia has the following wetland designations: Arid West, FAC; Atlantic and Gulf Coastal Plain, FACW; Great Plains, FACW; Western Mountains, Valleys, and Coast, FACW.
FAC, Facultative, Hydrophyte, Occur in wetlands and non-wetlands
FACW = Facultative Wetland, usually occur in wetlands, but may occur in non-wetlands
Threatened/Endangered Information: Unknown
Genus Information: In North America there are 24 species and 26 accepted taxa overall for Baccharis. World wide, The Plant List includes 430 accepted species names and includes a further 409 scientific plant names of infraspecific rank for the genus.
In the Southwestern United States: Arizona and California each have 10 species of Baccharis, Nevada has 5 species, New Mexico has 13 species, Texas has 12 species, Utah has 5 species. All data is approximate and subject to taxonomic changes.
Comments: Mule Fat or Seepwillow is a common, mostly riparian species forming thickets along permanent water. Individual smaller numbers of plants may be encountered in dry washes after loss of surface water. Although this shrub resembles a true willow tree and is often found in the same habitat types, it is not a member of the Salicaceae or willow family.