Calycadenia truncata
Rosin weed
Family: Asteraceae · Type: annual · Native
Rosin weed is a California native annual found in northwestern California, the Cascade Range, Sierra Nevada foothills, Central Valley, and central western California in dry, open hillsides, rocky ridges, grasslands, and foothill woodland openings at elevations of 50 to 1,600 meters. Flowering from May to October, this plant produces yellow ray flowers with heads generally 1 to 3 per node, creating distinctive clusters. Growing with reddish branched stems 20 to 120 centimeters tall that become somewhat rough toward the tips, it develops intricate branching beyond the middle of the plant. Its leaves reach up to 10 centimeters long, with proximal leaves showing the most pronounced development. The ray fruits are uniquely textured, with a rough, wrinkled surface that distinguishes this delicate annual wildflower.
Habitat: Common. Dry, open hillsides, rocky ridges, talus, grassland, openings in foothill woodland, scrub
Bloom period: May-Oct
Elevation: 50-1600 m
Bioregions: NW, CaR, SNF, n&c SNH, GV, CW
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Jepson eFlora, Cal-IPC, and more.