Hemizonella minima

Opposite leaved tarweed

Family: Asteraceae · Type: annual · Native

Opposite leaved tarweed is a California native annual found in the Klamath Ranges, northern Coast Ranges, Cascade Range, Sierra Nevada, southeastern San Francisco Bay Area, southern Coast Ranges, Transverse Ranges, Peninsular Ranges, and Modoc Plateau in gravelly or rocky open sites in scrub, meadows, and forest at elevations of 300 to 2,900 meters. Flowering from April to August, this plant produces pale yellow flowers in small heads 1 to 4 millimeters in diameter, with delicate ray flowers barely extending beyond the involucre. Growing with decumbent to erect stems 1 to 20 centimeters tall, the plant has widely divergent branches covered in minute coarse hairs with glandular stalks. Its leaves are distinctive, with lower leaves opposite and upper leaves alternate, linear and sessile, 5 to 25 millimeters long and less than 2.5 millimeters wide, covered in coarse hairs and glandular on the upper surfaces. The small black fruits are compressed, slightly arched, and tipped with a minute straight beak.

Habitat: Gravelly or rocky, generally open sites in scrub, meadows, forest

Bloom period: Apr-Aug

Elevation: 300-2900 m

Bioregions: KR, NCoR, CaR, SN, se SnFrB, SCoRI (San Benito Mtn), SCoRO (Hanging Valley, Santa Lucia Range), TR, PR, MP

California counties: Fresno, Kern, El Dorado, Los Angeles, Riverside, Tulare, Modoc, Siskiyou, Nevada, Tuolumne, Alpine, Mendocino, Amador, Calaveras, Lassen, Madera, Monterey, Placer, San Bernardino, San Diego, Santa Clara, Sierra, Ventura, Butte, Plumas, Glenn, Humboldt, Shasta, Lake, Mariposa, Tehama, Trinity, Mono, Colusa, Del Norte, Napa, Sonoma, Inyo, Santa Barbara

Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Jepson eFlora, Cal-IPC, and more.