Holocarpha heermannii
Heermann's tarweed
Family: Asteraceae · Type: annual · Native
Heermann's tarweed is a California native annual found in central Sierra Nevada Foothills, Tehama, San Joaquin Valley, eastern San Francisco Bay, southern Coast Ranges, and northern Western Transverse Ranges in grassland habitats at elevations below 1,400 meters. Flowering from May to November, this plant produces yellow flowers with yellow to brown anthers in heads with 3 to 13 ray flowers and 9 to 22 disk flowers. Growing with notably stalked-glandular stems that form panicle- or raceme-like clusters, it develops branches with distinctive flower heads. Its leaves are accompanied by heads with bell-shaped to nearly spherical involucres, each phyllary marked by 25 to 50 pit-gland-tipped outgrowths and minutely glandular surfaces. The plant's delicate, glandular structure and multiple flower heads make it a distinctive member of California's grassland ecosystems.
Habitat: Grassland
Bloom period: May-Nov
Elevation: < 1400 m
Bioregions: c&s SNF, Teh, SnJV, e SnFrB, SCoR, n WTR.
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Jepson eFlora, Cal-IPC, and more.