Bromus racemosus
Smooth brome
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Family: Poaceae · Type: Grass · Not Native
Bromus racemosus (Smooth brome) is a non-native California grass in the Poaceae family, recognized by narrow inflorescence with 1 spikelet per branch and glabrous lemmas.
Smooth brome is a naturalized annual grass found in the Klamath Ranges, northern California Coast Ranges, Sierra Nevada foothills, Central Valley, Central Coast, San Francisco Bay Area, and northern Channel Islands at elevations of 60 to 1,850 meters, commonly occurring in disturbed areas and along roadsides. Flowering from May to July, this grass produces small, narrow spikelets 11 to 18 millimeters long with green to tan coloration. Growing with tall stems 25 to 110 centimeters high, it features long-hairy lower leaf sheaths and narrow leaf blades 2 to 5 millimeters wide. Its lower leaves have ligules 1 to 3 millimeters long, with narrow inflorescences 4 to 14 centimeters in length bearing single spikelets on short branches. The grass produces lemmas with slender awns 5 to 9 millimeters long, characteristic of its distinctive grass structure.
Identification and appearance
Key characters: 33 sympatric species; key features are narrow inflorescence with 1 spikelet per branch and glabrous lemmas
Habitat and range
Habitat: Disturbed areas, roadsides
Elevation: 60-1850 m
California counties: Sonoma, Mendocino, Orange, Tuolumne, Siskiyou, Shasta, Santa Cruz, San Mateo, San Francisco, San Diego, Plumas, Nevada, Mariposa, Lassen, Contra Costa, Butte, San Bernardino, Tehama, Yuba, Trinity, Stanislaus, Marin, Alameda, Modoc, Lake, Los Angeles, Humboldt, Calaveras, Fresno, Sierra, Placer, Sacramento, Solano, San Joaquin, Yolo
Outside California: to British Columbia, eastern North America, native to Europe
Bloom period
Bromus racemosus blooms May-Jul.
How to tell it apart
vs Nassella: Bromus has closed leaf sheaths and large spikelets; Nassella has open sheaths and needle-like awns.; vs Hordeum: Bromus has separate large spikelets; Hordeum has three spikelets grouped at each node.; vs Avena: Bromus lemmas have two teeth at tip; Avena lemmas have a twisted awn from the back.; vs Lolium: Bromus spikelets are stalked in clusters; Lolium spikelets sit edgewise against the stem.; vs Festuca: Bromus leaf sheaths are closed; Festuca sheaths split open halfway down.
Frequently asked questions
Is Bromus racemosus native to California?
No. Bromus racemosus is not native to California (recorded as not native).
When does Bromus racemosus bloom?
Bromus racemosus blooms May-Jul.
Where in California does Bromus racemosus grow?
Bromus racemosus occurs in Sonoma, Mendocino, Orange, Tuolumne, Siskiyou, Shasta, Santa Cruz, San Mateo and other counties, at elevations of 60-1850 m.
What plant family does Bromus racemosus belong to?
Bromus racemosus is in the Poaceae family, genus Bromus.
What habitat does Bromus racemosus grow in?
Bromus racemosus grows in Disturbed areas, roadsides.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · Index of California Plant Names · CalPhotos
Last updated 2026-10-07
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.