Baccharis salicifolia |
Baccharis halimifolia |
|
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mule's fat, mule-fat, seepwillow, water wally |
consumption-weed, eastern baccharis, eastern false willow, sea-myrtle |
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Habit | Shrubs, 30–400 cm (stems clustered). | Shrubs or trees, 100–300(–600) cm (freely branched). |
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 or minutely scurfy, sometimes 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 or sessile; blades elliptic to broadly obovate or rhombic, main cauline rhombic, 30–50(–80) × 10–40(–60) mm (thick and firm), bases cuneate, margins entire proximally, usually coarsely serrate distal to middles (teeth 1–3 pairs), faces glabrous, gland-dotted, resinous (distal reduced, entire). |
Involucres | hemispheric; staminate 3–6 mm, pistillate involucres 3–6 mm. |
campanulate; staminate 3–5 mm, pistillate 3–5 mm. |
Pistillate florets | 50–150; corollas 2–3.5 mm. |
20–30; corollas 2.5–3.5 mm. |
Staminate florets | (10–)17–48; corollas 4–6 mm. |
25–30; 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). |
ovate to lanceolate, 1–4 mm, margins scarious, medians green, apices obtuse to acute. |
Heads | in terminal, compound corymbiform arrays (often involving distal branches). |
3–4 in loose pedunculate clusters in (terminal, leafy-bracted) broad paniculiform arrays. |
Cypselae | 0.8–1.5 mm, 5-nerved, glabrous; pappi 3–6 mm. |
1–1.8 mm, 8–10-nerved, glabrous; pappi 8–12 mm. |
2n | = 18, 36. |
= 18. |
Baccharis salicifolia |
Baccharis halimifolia |
|
Phenology | Flowering (Jan–)Mar–Oct. | Flowering Aug–Nov. |
Habitat | Stream banks, dry washes, sandy flood plains, riparian woodlands, disturbed sites, ditches | Open sandy places, wet fields, marshes, beaches, disturbed sites, roadsides, old fields |
Elevation | 30–2400 m (100–7900 ft) | 0–100 m (0–300 ft) |
Distribution |
AZ; CA; CO; NM; NV; TX; UT; Mexico; South America
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AL; AR; CT; DE; FL; GA; LA; MA; MD; MS; NJ; NY; OK; PA; RI; SC; TX; VA; NS; Mexico (Nuevo León, San Luis Potosí, Tamaulipas, Veracruz); West Indies [Introduced in Europe (France), Australia]
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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.) |
Native to the Atlantic and Gulf Coastal Plain, Baccharis halimifolia is recognized by its broad, distinctly rhombic, coarsely serrate basal leaves, pyramidal, leafy arrays, and cypselae with large fluffy pappi. The plants are often to 600 cm; the basal leaves might be missed by collectors. Forms with relatively narrow leaves are especially common in Arkansas, Louisiana, and east Texas. These may be the result of hybridization and introgression with B. neglecta, in areas where they are known to hybridize (D. J. Zanowiak 1991), or with B. angustifolia. Hybrids between B. halimifolia and B. angustifolia are known from Florida as well. Baccharis halimifolia has been introduced to Australia and France. In Australia it infests large areas along the coast of southern Queensland and New South Wales. Its success as an invasive weed is attributed to production of a large number of seeds that are widely dispersed by the wind, shade tolerant germination and seedlings, tolerance to wet soils and salinity, and ability to resprout after a fire (W. E. Westman et al. 1975). The leaves of B. halimifolia contain a cardiotoxic glycoside known to cause the death of sheep if they eat about one percent of their body weight in leaves. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 31. | FNA vol. 20, p. 28. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Molina salicifolia, B. viminea, B. viminea var. atwoodii | B. halimifolia var. angustior |
Name authority | (Ruiz & Pavón) Persoon: Syn. Pl. 2: 425. (1807) | Linnaeus: Sp. Pl. 2: 860. (1753) |
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