Laennecia coulteri

Coulter's horseweed

Family: Asteraceae · Type: annual · Native

Coulter's horseweed is a California native annual found in southern Sierra Nevada foothills, San Joaquin Valley, coastal western California, southwestern California, and southeastern desert regions in disturbed sites, clayey or sandy soils, often seasonally wet areas at elevations below 3,025 meters. Flowering from May to November, this plant produces small white to pale tan flowers in raceme- or panicle-like clusters with heads 2.5 to 3 millimeters long. Growing 10 to 50 centimeters tall with 1 to several stems branching from the base, becoming much-branched toward the upper portion. Its lower leaves are widely spoon-shaped to oblong, 2 to 7 centimeters long with obscure lobes or coarse teeth, while upper leaves become narrower and more finely toothed. The fruit is small, pale tan, with a delicate white pappus approximately 3.5 to 4 millimeters long.

Habitat: Disturbed sites, clayey or sandy soils, often seasonally wet, alkaline

Bloom period: May-Nov

Elevation: < 3025 m

Bioregions: s SNF, SnJV, CW, SW, SNE (exc W&ampI), D

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