Baccharis salicifolia |
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mule's fat, mule-fat, seepwillow, water wally |
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Habit | Shrubs, 30–400 cm (stems clustered). |
Stems | spreading to ascending, green to tan, simple proximally, sparingly branched distally, striate-angled, glabrous or minutely hairy, resinous and ± resin-varnished. |
Leaves | 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. |
Involucres | hemispheric; staminate 3–6 mm, pistillate involucres 3–6 mm. |
Pistillate florets | 50–150; corollas 2–3.5 mm. |
Staminate florets | (10–)17–48; corollas 4–6 mm. |
Phyllaries | 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). |
Heads | in terminal, compound corymbiform arrays (often involving distal branches). |
Cypselae | 0.8–1.5 mm, 5-nerved, glabrous; pappi 3–6 mm. |
2n | = 18, 36. |
Baccharis salicifolia |
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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) |
Distribution |
AZ; CA; CO; NM; NV; TX; UT; Mexico; South America
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Discussion | 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 | |
Synonyms | Molina salicifolia, B. viminea, B. viminea var. atwoodii |
Name authority | (Ruiz & Pavón) Persoon: Syn. Pl. 2: 425. (1807) |
Web links |