Matricaria occidentalis
valley mayweed
1–5+, usually erect, sometimes ascending, simple or branched mostly distally, sometimes proximally (then ascending).
blades 1560(–80) × 5–28 mm.
1–56(–90) mm (glabrous or villosulous near heads, bracts 0–3, simple or 1-pinnate).
3.5–4.5 mm.
4.5–6.6 mm, rounded to obtuse or ± acute.
0.
400–750+;
corollas greenish yellow, 1.2–1.7 mm (sparsely glandular), lobes 4.
25–55+ in 3–4 series, margins erose.
discoid, 1–15+, borne singly or in open, corymbiform arrays.
tan to brownish, obtriangular-obconic (angular, abaxial faces rounded, adaxial faces slightly convex), 1–1.5 mm, ribs white (2 abaxial, 2 lateral, each with reddish brown mucilage gland in distal 1/2, glands expanding into lobes, 1 adaxial, usually obscure, sometimes with a gland), faces not glandular;
pappi coroniform, lobed (lobes 2, spreading, abaxio-lateral, ± obtuse to rounded).
ovoid to hemispheric, 5.5–12.5 × 6–14 mm.
= 18.
Matricaria occidentalis
E. McClintock (1993b) reported Matricaria occidentalis as being used as a substitute for chamomile. In California, the species is found in the Coast Ranges to the South Coast, in parts of the San Joaquin Valley, and in the High Cascade, Sierra Nevada, and Desert Ranges and surrounding areas. Although listed as secure, the species appears to have been eradicated from some counties in California and its range may be shrinking due to disappearance of its habitat.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
CA
OR
Flora NW
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
