Ageratina adenophora

Crofton weed, Crofton Weed

Family: Asteraceae · Type: perennial · Not Native

Conservation status: Cal-IPC Yes

Crofton weed is a naturalized perennial herb found in coastal California regions including the Central Coast, San Francisco Bay Area, southern coastal ranges, and southwestern California in disturbed places, streambanks, canyons, and hillslopes at elevations below 1,000 meters. Flowering throughout the year, this plant produces white or pink-tinged flowers in small heads approximately 6.5 millimeters long. Growing with erect stems 50 to 150 centimeters tall that are purplish and glandular-hairy, it develops a woody base. Its opposite leaves are large, 40 to 100 millimeters long, with deltate-ovate shapes, serrated edges, and a distinctive purple upper surface that is glandular-puberulent. The fruit is small, measuring 1.7 to 2 millimeters in length.

Habitat: Disturbed places, streambanks, canyons, hillslopes

Bloom period: All year

Elevation: < 1000 m

Bioregions: CCo, SnFrB, SCoRO, SW

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