Poa macrantha
Seashore blue grass, Seashore Blue Grass
(c) Matt Lavin, some rights reserved (CC BY-SA) · licence
Family: Poaceae · Type: Grass · Native
Poa macrantha (Seashore blue grass) is a native California grass in the Poaceae family, recognized by no sympatric species.
Seashore blue grass is a California native perennial found in northern coastal areas in coastal dunes at elevations below 100 meters. Flowering from May to July, this plant produces pale green to blue-green flowers in dense, narrowly ovate inflorescences 3 to 15 centimeters long. Growing with tufted stems 10 to 60 centimeters tall, it spreads through very long, stout rhizomes or stolons. Its leaves are firm and narrow, 2 to 4 millimeters wide, folded and inrolled with finely hairy upper surfaces. The plant is dioecious, with distinctive grass-like growth forming dense clumps along coastal environments.
Identification and appearance
Key characters: Geographically isolated; no sympatric species
Habitat and range
Habitat: Coastal dunes
Elevation: < 100 m
California counties: Humboldt, Mendocino, Del Norte, El Dorado
Outside California: to Alaska
Bloom period
Poa macrantha blooms May-Jul.
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 macrantha native to California?
Yes. Poa macrantha is native to California (recorded as native).
When does Poa macrantha bloom?
Poa macrantha blooms May-Jul.
Where in California does Poa macrantha grow?
Poa macrantha occurs in Humboldt, Mendocino, Del Norte, El Dorado, at elevations of < 100 m.
What plant family does Poa macrantha belong to?
Poa macrantha is in the Poaceae family, genus Poa.
What habitat does Poa macrantha grow in?
Poa macrantha grows in Coastal dunes.
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.