Baccharis bigelovii
Baccharis sarothroides
Bigelow's false willow
broom baccharis, desert broom, greasewood, groundsel, rosin-brush
erect to ascending, slender, striate-angled, glabrous, resinous.
erect, striate, sharply angled, green distally, glabrous, 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.
cauline (proximal withered and/or sparse at flowering);
sessile;
blades (1-nerved) linear-lanceolate, 5–15 × 1–2 mm, reduced to scales distally, thick, bases narrowed, margins entire (often revolute), apices acute, faces glabrous, minutely gland-dotted, resinous.
campanulate;
staminate 4–5 mm, pistillate 4–5 mm.
cylindric to hemispheric;
staminate 4–5.2 mm, pistillate 3–8 mm.
25–30;
corollas 2–2.6 mm.
19–31;
corollas 2.5–3.5 mm.
15–20;
corollas 3.5–4 mm.
18–35;
corollas 4.2–5 mm.
lanceolate, 1–4 mm, margins scarious, medians green, apices acute, erose.
ovate to lanceolate, 1–5 mm, margins yellowish, slightly scarious, medians green to yellow, apices rounded to acute (greenish, abaxial faces glabrous, resinous).
(20–50) in corymbiform arrays.
borne singly (on nearly leafless branches) or (laterally on branchlets) in dense paniculiform arrays.
1.5–2.2 mm, 5-nerved, glabrous;
pappi 3–4.5 mm.
2–2.6 mm, finely 8–10-nerved, glabrous;
pappi 7–12 mm.
= 18.
Baccharis bigelovii
Baccharis sarothroides
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.)
Baccharis sarothroides is recognized by its broomlike habit, narrow, sharply angular, nearly leafless, green stems, soon-withering proximal leaves, scalelike distal leaves, and heads often terminal on long branches. Specimens from California have smaller heads that sometimes are arranged laterally along the stems.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
WildflowerSearch
iNaturalist
USDA Plants Database
CA
