Baccharis salicifolia |
Baccharis bigelovii |
|
---|---|---|
mule's fat, mule-fat, seepwillow, water wally |
Bigelow's false willow |
|
Habit | Shrubs, 30–400 cm (stems clustered). | Shrubs, 30–100 cm (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 to ascending, 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- or obscurely 3-nerved) obovate to oblanceolate, 20–35 × 3–15 mm, distally reduced and narrowed, bases cuneate, margins irregularly incised to coarsely serrate or 2-serrate, faces glabrous, gland-dotted, resinous. |
Involucres | hemispheric; staminate 3–6 mm, pistillate involucres 3–6 mm. |
campanulate; staminate 4–5 mm, pistillate 4–5 mm. |
Pistillate florets | 50–150; corollas 2–3.5 mm. |
25–30; corollas 2–2.6 mm. |
Staminate florets | (10–)17–48; corollas 4–6 mm. |
15–20; corollas 3.5–4 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, apices acute, erose. |
Heads | in terminal, compound corymbiform arrays (often involving distal branches). |
(20–50) in corymbiform arrays. |
Cypselae | 0.8–1.5 mm, 5-nerved, glabrous; pappi 3–6 mm. |
1.5–2.2 mm, 5-nerved, glabrous; pappi 3–4.5 mm. |
2n | = 18, 36. |
|
Baccharis salicifolia |
Baccharis bigelovii |
|
Phenology | Flowering (Jan–)Mar–Oct. | Flowering Aug–Nov. |
Habitat | Stream banks, dry washes, sandy flood plains, riparian woodlands, disturbed sites, ditches | Dry rocky ground in coniferous forests |
Elevation | 30–2400 m [100–7900 ft] | 1300–2000 m [4300–6600 ft] |
Distribution |
AZ; CA; CO; NM; NV; TX; UT; Mexico; South America
|
AZ; NM; TX; Mexico (Chihuahua, Durango, Sonora) |
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.) |
Baccharis bigelovii occurs in the general Chihuahuan Desert region in the Davis Mountains of West Texas, and in the Chiricahua and Huachuca mountains of Arizona. It is recognized by the relatively short stature, obovate, coarsely and irregularly serrate leaves, erose-ciliate phyllaries, and 5-nerved cypselae. It is similar to B. thesioides, which differs mainly by having narrower, more oblong leaves with more evenly serrate margins and spinulose teeth. Further investigation may show these two taxa to be different geographic expressions of a single species centered in Mexico. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 31. | FNA vol. 20, p. 26. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Molina salicifolia, B. viminea, B. viminea var. atwoodii | |
Name authority | (Ruiz & Pavón) Persoon: Syn. Pl. 2: 425. (1807) | A. Gray: in W. H. Emory, Rep. U.S. Mex. Bound. 2(1): 84. (1859) |
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