Baccharis salicifolia is a blooming shrub native to the sage scrub community and desert southwest of the United States and northern Mexico, as well as parts of South America.

Its usual common name is mule fat;[3]: 126  it is also called seepwillow or water-wally.

This is a large bush with sticky foliage which bears plentiful small, fuzzy, pink, or red-tinged white flowers which are highly attractive to butterflies.

[5] The long pointed leaves may be toothed and contain three lengthwise veins.

Mulefat plays host to several gall-inducing insect species including Aceria baccharices.