Poa atropurpurea
San bernardino bluegrass, San Bernardino Blue Grass
(c) Matt Berger, some rights reserved (CC BY) · licence
Family: Poaceae · Type: Grass · Native
Conservation status: CNPS 1B.2 · Endangered
Poa atropurpurea (San bernardino bluegrass) is a native California grass in the Poaceae family, recognized by unique dioecious habit and rhizomatous growth.
San bernardino bluegrass is a rare (CNPS 1B.2) California native perennial found in the San Bernardino Mountains and Peninsular Ranges in moist meadows at elevations of 1,250 to 2,320 meters. Flowering from April to June, this plant produces purple-tinted spikelets in compact clusters with delicate inflorescences. Growing in dense tufts 10 to 55 centimeters tall with spreading rhizomes, it forms elegant clumped formations in mountain grasslands. Its narrow leaves are firm and tightly folded, measuring 1.5 to 3 millimeters wide, with short ligules 1 to 2 millimeters long. The plant is dioecious, with separate male and female plants producing distinctive, glabrous spikelets 2.5 to 3.5 millimeters long.
Identification and appearance
Key characters: 22 sympatric species; unique dioecious habit and rhizomatous growth
Habitat and range
Habitat: Moist meadows
Elevation: 1250-2320 m
California counties: San Bernardino, San Diego
Bloom period
Poa atropurpurea blooms Apr-Jun.
Conservation status
CNPS 1B.2 · Endangered
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 atropurpurea native to California?
Yes. Poa atropurpurea is native to California (recorded as native).
When does Poa atropurpurea bloom?
Poa atropurpurea blooms Apr-Jun.
Where in California does Poa atropurpurea grow?
Poa atropurpurea occurs in San Bernardino, San Diego, at elevations of 1250-2320 m.
What plant family does Poa atropurpurea belong to?
Poa atropurpurea is in the Poaceae family, genus Poa.
Is Poa atropurpurea rare or endangered?
Poa atropurpurea carries California Rare Plant Rank 1B.2, state rank S2.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · CNPS Rare Plant Inventory · Index of California Plant Names · CalPhotos · CDFW CNDDB
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.