The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

mule's fat, mule-fat, seepwillow, water wally

Habit Shrubs, 30–400 cm (stems clustered).

spreading to ascending, green to tan, simple proximally, sparingly branched distally, striate-angled, glabrous or minutely hairy, resinous and ± resin-varnished.


present at flowering (abundant, well developed);

sessile or petiolate;

blades lanceolate-elliptic, slightly falcate (willowlike), 30–150 × 3–20 mm, bases attenuate, margins usually finely serrate from bases to apices, sometimes entire, apices acute to acuminate, faces glabrous, gland-dotted, ± resinous.


hemispheric; staminate 3–6 mm, pistillate involucres 3–6 mm.

Pistillate florets


corollas 2–3.5 mm.

Staminate florets


corollas 4–6 mm.


ovate to lanceolate, 2–4 mm, margins scarious, erose or irregularly dentate, midribs distinct, medians green or reddish, apices (greenish or brownish purple) obtuse to acuminate (pale and dry, glabrous).


in terminal, compound corymbiform arrays (often involving distal branches).


0.8–1.5 mm, 5-nerved, glabrous;

pappi 3–6 mm.


= 18, 36.

Baccharis salicifolia

Phenology Flowering (Jan–)Mar–Oct.
Habitat Stream banks, dry washes, sandy flood plains, riparian woodlands, disturbed sites, ditches
Elevation 30–2400 m (100–7900 ft)
from FNA
AZ; CA; CO; NM; NV; TX; UT; Mexico; South America
[WildflowerSearch map]
[BONAP county map]

Baccharis salicifolia is part of a complex that extends through the southwestern United States, Mexico, Central America, and South America to Argentina and Chile (J. Cuatrecasas 1968). It is recognized by the narrowly lanceolate, willowlike, finely serrate leaves with acute or acuminate apices, smallish heads in dense clusters, reddish phyllaries, and 5-nerved cypselae. By tagging and measuring individual plants throughout the year, D. H. Wilken (1972) demonstrated that B. salicifolia has distinct seasonal forms. The North American plants were once known as B. glutinosa or B. viminea, which were differentiated from each other by differences in woodiness, leaf size and serration, and flowering time.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 20, p. 31.
Parent taxa Asteraceae > tribe Astereae > Baccharis
Sibling taxa
B. angustifolia, B. bigelovii, B. brachyphylla, B. dioica, B. glomeruliflora, B. glutinosa, B. halimifolia, B. havardii, B. malibuensis, B. neglecta, B. pilularis, B. plummerae, B. pteronioides, B. salicina, B. sarothroides, B. sergiloides, B. texana, B. thesioides, B. vanessae, B. wrightii
Synonyms Molina salicifolia, B. viminea, B. viminea var. atwoodii
Name authority (Ruiz & Pavón) Persoon: Syn. Pl. 2: 425. (1807)
Web links