Hordeum murinum subsp. glaucum
Smooth barley, Smooth Barley
Photo: parent species Hordeum murinum · Photo by Chez Brungraber
Family: Poaceae · Type: Grass · Not Native
Hordeum murinum subsp. glaucum (Smooth barley) is a non-native California grass in the Poaceae family, recognized by summer annual habit, brown color at maturity, small central florets.
Smooth barley is a naturalized annual grass found throughout California, except in the Klamath Ranges, Cascade Range, and Great Basin, inhabiting moist and generally disturbed sites at elevations from 60 meters below sea level to 1,900 meters. Flowering from March to July, this plant produces green to glaucous inflorescences that turn brown as they mature, with distinctive awned spikelets. Growing with slender stems 15 to 40 centimeters tall, it spreads easily in disrupted landscapes. Its leaves are narrow and grass-like, typical of the barley genus, with smooth green to bluish-green blades. The distinctive inflorescence features central and lateral spikelets with long, delicate awns that help distinguish it from native grass species.
Identification and appearance
Key characters: 10 sympatric species; key features are summer annual habit, brown color at maturity, small central florets
Habitat and range
Habitat: Moist, generally disturbed sites
Elevation: -60-1900 m
California counties: Ventura, Los Angeles, Kern, Santa Barbara, Tuolumne, Riverside, Sacramento, Sonoma, San Bernardino, Inyo, San Joaquin, Imperial, Siskiyou, Humboldt, Tehama, San Diego, Contra Costa, Stanislaus, Solano, Monterey, Marin, Napa, San Francisco, Lake, Alameda, San Mateo, Santa Cruz, Amador, Glenn, Colusa, Orange, San Benito, San Luis Obispo, Santa Clara, Tulare, Placer, Yolo, Lassen, Sutter, Nevada, Yuba, Calaveras, Mariposa, Merced, Mono, Kings, Trinity, Madera, Fresno, Butte, Modoc, Shasta, Mendocino, El Dorado
Outside California: to British Columbia, Oklahoma, Alabama, Texas, Mexico
Bloom period
Hordeum murinum subsp. glaucum blooms Mar-Jul.
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 subsp. glaucum native to California?
No. Hordeum murinum subsp. glaucum is not native to California (recorded as not native).
When does Hordeum murinum subsp. glaucum bloom?
Hordeum murinum subsp. glaucum blooms Mar-Jul.
Where in California does Hordeum murinum subsp. glaucum grow?
Hordeum murinum subsp. glaucum occurs in Ventura, Los Angeles, Kern, Santa Barbara, Tuolumne, Riverside, Sacramento, Sonoma and other counties, at elevations of -60-1900 m.
What plant family does Hordeum murinum subsp. glaucum belong to?
Hordeum murinum subsp. glaucum is in the Poaceae family, genus Hordeum.
What habitat does Hordeum murinum subsp. glaucum grow in?
Hordeum murinum subsp. glaucum grows in Moist, generally disturbed sites.
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.