Baccharis thesioides
Baccharis salicifolia
Arizona baccharis, Mogollon baccharis
mule's fat, mule-fat, seepwillow, water wally
erect to ascending, slender, striate-angled, glabrous, scarcely resinous.
spreading to ascending, green to tan, simple proximally, sparingly branched distally, striate-angled, glabrous or minutely hairy, resinous and ± resin-varnished.
usually present at flowering;
sessile;
blades (1-nerved) linear-oblanceolate to narrowly oblong, 20–40(–80) × 4–8 mm, bases cuneate, margins evenly serrate (teeth spinulose, apices acute, faces finely gland-dotted, not resinous).
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.
campanulate; staminate 3–6 mm, pistillate 3–6 mm.
hemispheric; staminate 3–6 mm, pistillate involucres 3–6 mm.
30;
corollas 2.2–3 mm.
50–150;
corollas 2–3.5 mm.
20–30;
corollas 3 mm.
(10–)17–48;
corollas 4–6 mm.
lanceolate, 1–5 mm, margins scarious, erose-ciliate, medians green, apices acute or obtuse (erose, abaxial faces glabrous).
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).
(10–50+) in terminal, compact, rounded paniculiform arrays.
in terminal, compound corymbiform arrays (often involving distal branches).
1.5–2.2 mm, 5-nerved, glabrous;
pappi 4–6 mm.
0.8–1.5 mm, 5-nerved, glabrous;
pappi 3–6 mm.
= 18, 36.
Baccharis thesioides
Baccharis salicifolia
Baccharis thesioides is recognized by its erect stems, narrow, oblong, evenly serrate leaves with finely spinulose teeth, heads in relatively small rounded arrays, and 5-ribbed cypselae with short pappi. It is sometimes confused with B. bigelovii, which has broader and irregularly serrate leaves. The two taxa may belong to the same species complex centered in Mexico.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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.)
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USDA Plants Database
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CalFlora
Flora NW
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