Ambrosia monogyra

Singlewhorl burrobrush, singlewhorl burrobrush, singlewhorl burrobrush

Family: Asteraceae · Type: shrub · Native

Conservation status: CNPS 2B.2

Singlewhorl burrobrush is a rare (CNPS 2B.2) California native shrub found in southwestern California, eastern Sierra Nevada, and desert southern regions in washes and dry riverbeds at elevations below 500 meters. Flowering from September to November, this plant produces small, inconspicuous heads of staminate and pistillate flowers in tight clusters. Growing as a much-branched shrub 1 to 4 meters tall with glabrous, resinous stems, it forms an open, leafy panicle-like structure. Its distinctive leaves are 2 to 5 centimeters long, thread-like or with few thread-like lobes, with grooved upper surfaces and glabrous, resinous undersides. The fruit is a distinctive bur 2 to 5 millimeters long with 7 to 12 wings arranged in a single central whorl.

Habitat: Washes, dry riverbeds

Bloom period: Sep-Nov

Elevation: < 500 m

Bioregions: SW, SNE, DSon

California counties: San Diego, San Bernardino, Imperial, Inyo

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