Poa glauca subsp. rupicola
Timberline blue grass, Timberline Blue Grass
Chase, Agnes; Hitchcock, A. S. (via Wikimedia Commons) · CC0
Family: Poaceae · Type: Grass · Native
Poa glauca subsp. rupicola (Timberline blue grass) is a native California grass in the Poaceae family, recognized by all shoots flowering and very short inflorescence branches.
Timberline blue grass is a California native perennial found in the Sierra Nevada and White and Inyo Mountains on dry alpine slopes and ridges at elevations of 3,300 to 4,100 meters. Flowering from July to August, this plant produces pale blue to green flowers in compact, narrow inflorescences 1 to 5 centimeters long. Growing as a densely tufted grass 5 to 15 centimeters tall with all current shoots flowering, it forms tight, cushion-like clusters. Its leaf blades are narrow, 1 to 2 millimeters wide, soft, and either flat or slightly folded, with open sheaths extending more than four-fifths of their length. The plant's flower spikelets have glumes 2.5 to 3.5 millimeters long, with lemmas bearing short hairs at the base.
Identification and appearance
Key characters: 30 sympatric species; all shoots flowering and very short inflorescence branches
Habitat and range
Habitat: Dry alpine slopes, ridges
Elevation: 3300-4100 m
California counties: Inyo, Tulare, Mono, Fresno, Tuolumne, Sierra, Alpine, Mariposa, Madera, Nevada, Siskiyou
Outside California: to southwestern Canada, New Mexico
Bloom period
Poa glauca subsp. rupicola blooms Jul-Aug.
How to tell it apart
vs Festuca: Poa has boat-shaped, keeled leaf tips; Festuca leaves are flat or rolled but never keeled like a ship's prow.; vs Melica: Poa has fine, narrow leaves with boat-shaped tips; Melica has wider, flat leaves without the distinctive keel.; vs Nassella: Poa leaves have boat-shaped tips you can feel; Nassella leaves roll inward and lack the keel.; vs Koeleria: Poa has cobwebby hairs at seed base and keeled leaf tips; Koeleria lacks both features.; vs Holcus: Poa has boat-shaped leaf tips; Holcus leaves are flat and soft-hairy without any keel.
Frequently asked questions
Is Poa glauca subsp. rupicola native to California?
Yes. Poa glauca subsp. rupicola is native to California (recorded as native).
When does Poa glauca subsp. rupicola bloom?
Poa glauca subsp. rupicola blooms Jul-Aug.
Where in California does Poa glauca subsp. rupicola grow?
Poa glauca subsp. rupicola occurs in Inyo, Tulare, Mono, Fresno, Tuolumne, Sierra, Alpine, Mariposa and other counties, at elevations of 3300-4100 m.
What plant family does Poa glauca subsp. rupicola belong to?
Poa glauca subsp. rupicola is in the Poaceae family, genus Poa.
What habitat does Poa glauca subsp. rupicola grow in?
Poa glauca subsp. rupicola grows in Dry alpine slopes, ridges.
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.