Bromus arenarius
Australian chess, Australian Chess
no rights reserved, uploaded by Peter de Lange · CC0
Family: Poaceae · Type: Grass · Not Native
Bromus arenarius (Australian chess) is a non-native California grass in the Poaceae family, recognized by S-curved branches and tiny anthers diagnostic.
Australian chess is a naturalized annual grass found in the California Floristic Province and Desert bioregions in open, disturbed places at elevations below 2,000 meters. Flowering from April to July, this plant produces pale green to tan spikelets with nodding branches that curve dramatically like an S-shape. Growing 15 to 60 centimeters tall with hairy stems and spreading branches, it has a loose, open growth habit characteristic of disturbed landscapes. Its leaves are soft and hairy, with narrow blades 2 to 5 millimeters wide and small ligules measuring 1.5 to 2.5 millimeters long. The spikelets feature delicate hairy glumes and lemmas with slender awns 9 to 14 millimeters long, emerging just below the tip.
Identification and appearance
Key characters: 34 sympatric species; S-curved branches and tiny anthers diagnostic
Habitat and range
Habitat: Open, disturbed places
Elevation: < 2000 m
California counties: San Luis Obispo, Los Angeles, Colusa, Fresno, Glenn, Kern, Mendocino, Monterey, Riverside, San Benito, San Bernardino, San Diego, Santa Barbara, Tulare, Tuolumne, Inyo, Lake, Madera, Mariposa, Santa Clara, Stanislaus, Ventura, San Joaquin, Tehama, Santa Cruz, El Dorado, Alameda, Placer, San Mateo, Calaveras, Merced, Yolo, Napa, Sacramento, Imperial
Outside California: to Oregon, Arizona, native to Australia
Bloom period
Bromus arenarius blooms Apr-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 arenarius native to California?
No. Bromus arenarius is not native to California (recorded as not native).
When does Bromus arenarius bloom?
Bromus arenarius blooms Apr-Jul.
Where in California does Bromus arenarius grow?
Bromus arenarius occurs in San Luis Obispo, Los Angeles, Colusa, Fresno, Glenn, Kern, Mendocino, Monterey and other counties, at elevations of < 2000 m.
What plant family does Bromus arenarius belong to?
Bromus arenarius is in the Poaceae family, genus Bromus.
What habitat does Bromus arenarius grow in?
Bromus arenarius grows in Open, disturbed places.
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.