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

chaparral broom, coyote brush, dwarf chaparral false willow

Habit Shrubs, 30–400 cm (stems clustered). Shrubs, 15–450 cm (prostrate and mat-forming to erect and rounded, much branched).

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

spreading to ascending, dark brown, shiny, striate-angular, glabrous, often ± scurfy, usually resinous and sticky.


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.

present at flowering;

sessile or short-petiolate;

blades (1- or 3-nerved) oblanceolate to obovate, the smaller 5–40 × 2–15 mm (thick), bases cuneate, margins entire or coarsely dentate (teeth 3–9 distal to middles), faces glabrous, gland-dotted, resinous.


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

hemispheric to campanulate; staminate 3.2–5 mm, pistillate 3–6 mm.

Pistillate florets


corollas 2–3.5 mm.


corollas 2.5–3.5 mm.

Staminate florets


corollas 4–6 mm.

20–34, 3–4 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).

ovate to lanceolate, 1–3 mm, margins yellowish, scarious, medians yellow proximally, green distally, apices obtuse to acute or acuminate (erose, abaxial faces papillose-scurfy).


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

(100–200+) in (leafy) paniculiform arrays.


0.8–1.5 mm, 5-nerved, glabrous;

pappi 3–6 mm.

1–2 mm, 8–10-nerved, glabrous;

pappi 6–9 mm.


= 18, 36.

Baccharis salicifolia

Baccharis pilularis

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]
from FNA
CA; NM; OR; nw Mexico
[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.)

Subspecies 2 (2 in the flora).

Baccharis pilularis can be distinguished by its dark brown stems, and serrate, obovate to oblanceolate leaves. In addition, plants from some dunes of the California coast are prostrate, a growth form unique to this genus in our region.

The common, weedy, widespread form is subsp. consanguinea, which is typically erect, with its larger leaves 15–40 mm. Subspecies pilularis is known only from exposed sandy dunes and bluffs along the central coast of California. Its growth habit is matlike, and its larger leaves are 5–15 mm. The prostrate habit of subsp. pilularis is strikingly different from the upright habit of subsp. consanguinea.

C. B. Wolf (1935) demonstrated that in at least some populations, the distinction between prostrate and erect forms has a genetic basis. Transplants from the wild of the prostrate and erect forms retained their respective growth habits when grown together in a sheltered location and the morphology of seedlings reflected the habit of the parents. Wolf’s arguments for recognizing the forms as subspecies are further supported by the existence of prostrate cultivars in the horticultural trade. On the other hand, both erect and prostrate forms grow in proximity throughout the range of subsp. pilularis. In many areas the forms intergrade completely; in others they can be easily distinguished. Two subspecies are recognized here, notwithstanding difficulties in identifying habit from pressed specimens, or by observations of populations where both growth forms coexist. Further study is needed, perhaps utilizing molecular characters and detailed observations of native populations.

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

1. Stems erect, rarely prostrate, brittle, forming erect or rounded shrubs; leaves mostly 15–40 mm; noncoastal and coastal California, Oregon
subsp. consanguinea
1. Stems prostrate, flexible, forming mats; leaves mostly 5–15 mm; sandy, exposed habitats of coastal California
subsp. pilularis
Source FNA vol. 20, p. 31. FNA vol. 20, p. 29.
Parent taxa Asteraceae > tribe Astereae > Baccharis 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
B. angustifolia, B. bigelovii, B. brachyphylla, B. dioica, B. glomeruliflora, B. glutinosa, B. halimifolia, B. havardii, B. malibuensis, B. neglecta, B. plummerae, B. pteronioides, B. salicifolia, B. salicina, B. sarothroides, B. sergiloides, B. texana, B. thesioides, B. vanessae, B. wrightii
Subordinate taxa
B. pilularis subsp. consanguinea, B. pilularis subsp. pilularis
Synonyms Molina salicifolia, B. viminea, B. viminea var. atwoodii
Name authority (Ruiz & Pavón) Persoon: Syn. Pl. 2: 425. (1807) de Candolle: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 5: 407. (1836)
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