Baccharis salicifolia |
Baccharis havardii |
|
---|---|---|
mule's fat, mule-fat, seepwillow, water wally |
Havard's false willow |
|
Habit | Shrubs, 30–400 cm (stems clustered). | Subshrubs, 15–70 cm (much branched from bases). |
Stems | spreading to ascending, green to tan, simple proximally, sparingly branched distally, striate-angled, glabrous or minutely hairy, resinous and ± resin-varnished. |
erect (green to tan), slender, striate-angled, glabrous, resinous. |
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. |
present at flowering; short-petiolate; blades (1-nerved) narrowly spatulate to linear, 20–40 × 2–3 mm, reduced to bracts distally, bases attenuate, margins entire or toothed (teeth to 2 mm), faces glabrous, gland-dotted, resinous. |
Involucres | hemispheric; staminate 3–6 mm, pistillate involucres 3–6 mm. |
cylindro-campanulate; staminate 3 mm, pistillate 4–4.5 mm. |
Pistillate florets | 50–150; corollas 2–3.5 mm. |
15–20; corollas 3 mm. |
Staminate florets | (10–)17–48; corollas 4–6 mm. |
12–15; corollas 3–4 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). |
lanceolate, 1–4 mm, margins scarious, medians green or brownish, apices obtuse to acuminate (thickened, slightly erose and ciliate). |
Heads | in terminal, compound corymbiform arrays (often involving distal branches). |
in broad paniculiform arrays. |
Cypselae | 0.8–1.5 mm, 5-nerved, glabrous; pappi 3–6 mm. |
2–2.5 mm, 5-nerved, glabrous; pappi 4 mm. |
2n | = 18, 36. |
|
Baccharis salicifolia |
Baccharis havardii |
|
Phenology | Flowering (Jan–)Mar–Oct. | Flowering Jul–Sep. |
Habitat | Stream banks, dry washes, sandy flood plains, riparian woodlands, disturbed sites, ditches | Dry rocky hillsides, open ground, calcareous gravels |
Elevation | 30–2400 m (100–7900 ft) | 1500–2300 m (4900–7500 ft) |
Distribution |
AZ; CA; CO; NM; NV; TX; UT; Mexico; South America
|
NM; TX; Mexico (Chihuahua) |
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.) |
Found mainly in the Chisos and Davis Mountains of West Texas, Baccharis havardii is distinguished by its short bushy habit, narrow leaves with elongate teeth, and 5-nerved cypselae. G. L. Nesom (pers. comm.) suggested that it is weakly defined and further investigation may demonstrate it should be included in the Mexican species B. sulcata de Candolle (which name would have priority over B. havardii). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 31. | FNA vol. 20, p. 28. |
Parent taxa | Asteraceae > tribe Astereae > Baccharis | 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) | A. Gray: in A. Gray et al., Syn. Fl. N. Amer. 1(2): 224. (1884) |
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