Hordeum murinum
Wall barley, Wall Barley
Photo by Chez Brungraber
Family: Poaceae · Type: Grass · Not Native
Conservation status: Cal-IPC Yes
Hordeum murinum (Wall barley) is a non-native California grass in the Poaceae family, recognized by no sympatric species.
Wall barley is a naturalized annual grass found throughout California's agricultural and disturbed landscapes at low to moderate elevations. Flowering from March to June, this plant produces green to glaucous seed heads occasionally tinged with reddish or brownish tones, with distinctive awned spikelets 3 to 12 centimeters long. Growing with erect or sometimes prostrate stems 15 to 110 centimeters tall, it has smooth or slightly hairy stems with nodes that remain glabrous. Its leaf blades are narrow, 2 to 5 millimeters wide and up to 28 centimeters long, with glabrous or scarcely hairy surfaces. The seed heads are notable for their breaking axis and long awns measuring 20 to 50 millimeters, which give the plant a distinctive bristly appearance.
Identification and appearance
Key characters: Geographically isolated; no sympatric species
Habitat and range
California counties: Los Angeles, Riverside, San Luis Obispo, San Bernardino, Yolo, Orange, Imperial, Fresno, Kern, San Diego, Tulare, Glenn, Ventura, Santa Barbara, Alameda, Inyo, Kings, Santa Cruz, El Dorado, Amador, Colusa, San Joaquin, Placer, Contra Costa, Tehama, Humboldt, San Francisco, Butte, Alpine, San Mateo, Solano, Sonoma, Monterey, Napa, Sacramento, Mariposa, Lake, Sutter, Marin, Santa Clara
Conservation status
Cal-IPC Yes
How to tell it apart
vs Bromus: Hordeum has three spikelets per node in a spike; Bromus has separate spikelets in loose clusters.; vs Triticum: Hordeum has three spikelets per node; Triticum has one spikelet per node.; vs Taeniatherum: Hordeum has the central spikelet stalkless; check if side spikelets are stalked.; vs Setaria: Hordeum has three grouped spikelets per node; Setaria has dense bristly single spikelets.; vs Elymus: Hordeum has hollow stems; Elymus has solid stems between nodes.
Frequently asked questions
Is Hordeum murinum native to California?
No. Hordeum murinum is not native to California (recorded as not native).
Where in California does Hordeum murinum grow?
Hordeum murinum occurs in Los Angeles, Riverside, San Luis Obispo, San Bernardino, Yolo, Orange, Imperial, Fresno and other counties.
What plant family does Hordeum murinum belong to?
Hordeum murinum is in the Poaceae family, genus Hordeum.
Is Hordeum murinum invasive in California?
Hordeum murinum is listed by Cal-IPC with an invasiveness rating of Yes.
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.