Ambrosia confertiflora

Weak leaved burweed

Family: Asteraceae · Type: perennial · Native

Weak leaved burweed is a California native perennial found in the San Joaquin Valley, central coast, southern coast, and eastern Mojave Desert in disturbed areas at elevations below 1,250 meters. Flowering from July to October, this plant produces small green and white flower heads in dense raceme-like clusters. Growing with strigose stems 30 to 180 centimeters tall that emerge from rhizome-like roots, it has a spreading, somewhat bristly habit. Its leaves are sessile or short-petioled, with divided blades less than 16 centimeters long that are roughly ovate and pinnately lobed. The distinctive fruit is a small bur with 5 to 12 spiraled spines, which are cylindric and hooked, measuring 2 to 5 millimeters across.

Habitat: Disturbed areas

Bloom period: Jul-Oct

Elevation: < 1250 m

Bioregions: SnJV, CCo, SCo, e DMoj

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