Ambrosia acanthicarpa

Annual bur-sage, Annual Bur-Sage

Family: Asteraceae · Type: annual · Native

Annual bur-sage is a California native annual found in the North Coast Ranges, Sierra Nevada, San Joaquin Valley, Central Western California, southwestern deserts, Great Basin, and Mojave Desert in sandy plains and disturbed sites at elevations from 30 meters below sea level to 2,450 meters. Flowering from July to December, this plant produces pale yellow or greenish flower heads in small clusters, with distinctive staminate heads 2 to 5 millimeters in diameter. Growing with one to several ascending branches from a slender taproot, it reaches 40 to 150 centimeters tall and has a grayish, bristly appearance. Its lower leaves are opposite with large petioles 1 to 6 centimeters long, featuring deltate blades 1 to 8 centimeters wide that are shallowly lobed or pinnately divided. The fruit is a distinctive bur 5 to 7 millimeters long, golden or dark purple, with up to 30 sharp, spiraled spines that help with seed dispersal.

Habitat: Sandy plains, disturbed sites, many communities

Bloom period: Jul-Dec

Elevation: -30-2450 m

Bioregions: NCoR, SN, SnJV, CW, SW, GB, D

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