Baccharis sarothroides
Baccharis thesioides
broom baccharis, desert broom, greasewood, groundsel, rosin-brush
Arizona baccharis, Mogollon baccharis
erect, striate, sharply angled, green distally, glabrous, resinous.
erect to ascending, slender, striate-angled, glabrous, scarcely 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.
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).
cylindric to hemispheric;
staminate 4–5.2 mm, pistillate 3–8 mm.
campanulate;
staminate 3–6 mm, pistillate 3–6 mm.
19–31;
corollas 2.5–3.5 mm.
30;
corollas 2.2–3 mm.
18–35;
corollas 4.2–5 mm.
20–30;
corollas 3 mm.
ovate to lanceolate, 1–5 mm, margins yellowish, slightly scarious, medians green to yellow, apices rounded to acute (greenish, abaxial faces glabrous, resinous).
lanceolate, 1–5 mm, margins scarious, erose-ciliate, medians green, apices acute or obtuse (erose, abaxial faces glabrous).
borne singly (on nearly leafless branches) or (laterally on branchlets) in dense paniculiform arrays.
(10–50+) in terminal, compact, rounded paniculiform arrays.
2–2.6 mm, finely 8–10-nerved, glabrous;
pappi 7–12 mm.
1.5–2.2 mm, 5-nerved, glabrous;
pappi 4–6 mm.
= 18.
Baccharis sarothroides
Baccharis thesioides
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.)
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.)
CA
WildflowerSearch
iNaturalist
USDA Plants Database
