Agrostis oregonensis
Oregon redtop, Oregon Redtop
Hitchcock, A.S. (rev. A. Chase). 1950. Manual of the grasses of the United States. USDA Misc. Publ. No. 200. Washington, DC. 1950. (via Wikimedia Commons) · CC0
Family: Poaceae · Type: Grass · Native
Agrostis oregonensis (Oregon redtop) is a native California grass in the Poaceae family, recognized by very long basal leaves, moist habitat, and short or absent awns.
Oregon redtop is a California native perennial grass found in the Klamath Ranges, northern Coast Ranges, Cascade Range, Sierra Nevada, San Bernardino Mountains, and San Jacinto Mountains in moist areas, meadows, and streambanks at elevations below 2,400 meters. Flowering from June to July, this grass produces delicate, open panicles with thread-like branches and small greenish-white spikelets. Growing 12 to 75 centimeters tall with ascending branches, it forms loose, spreading tufts of slender stems. Its leaf blades are flat, 10 to 30 centimeters long and 2 to 4 millimeters wide, with ligules 2 to 4.5 millimeters long. Its lemmas are 1.5 to 2.5 millimeters long, occasionally bearing a short straight awn less than 2 millimeters in length.
Identification and appearance
Key characters: 14 sympatric species; key features are very long basal leaves, moist habitat, and short or absent awns
Habitat and range
Habitat: Moist areas, meadows, streambanks
Elevation: < 2400 m
California counties: Humboldt, Inyo, Mendocino, Tuolumne, Riverside, San Bernardino, Sonoma, Del Norte, El Dorado, Placer, Siskiyou, Shasta, Plumas, Mono, Fresno, Sierra, Lassen, Trinity, Nevada, Mariposa
Outside California: to British Columbia, Montana, Wyoming
Bloom period
Agrostis oregonensis blooms Jun-Jul.
How to tell it apart
vs Oloptum: Oloptum has prominent bent awns; Agrostis awns are tiny or absent.; vs Holcus: Holcus has velvety-hairy spikelets; Agrostis spikelets are smooth and glossy.; vs Polypogon: Polypogon has dense bristly panicles; Agrostis panicles are airy and delicate.; vs Poa: Poa has boat-shaped lemmas with 5 veins; Agrostis lemmas are rounded with faint veins.; vs Festuca: Festuca has multiple flowers per spikelet; Agrostis has single-flowered spikelets.
Frequently asked questions
Is Agrostis oregonensis native to California?
Yes. Agrostis oregonensis is native to California (recorded as native).
When does Agrostis oregonensis bloom?
Agrostis oregonensis blooms Jun-Jul.
Where in California does Agrostis oregonensis grow?
Agrostis oregonensis occurs in Humboldt, Inyo, Mendocino, Tuolumne, Riverside, San Bernardino, Sonoma, Del Norte and other counties, at elevations of < 2400 m.
What plant family does Agrostis oregonensis belong to?
Agrostis oregonensis is in the Poaceae family, genus Agrostis.
What habitat does Agrostis oregonensis grow in?
Agrostis oregonensis grows in Moist areas, meadows, streambanks.
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.