Poa lettermanii
Letterman's blue grass
(c) Cheng-Tao Lin, some rights reserved (CC BY), uploaded by Cheng-Tao Lin · licence
Family: Poaceae · Type: Grass · Native
Conservation status: CNPS 2B.3
Poa lettermanii (Letterman's blue grass) is a native California grass in the Poaceae family, recognized by extreme high elevation and tiny stature.
Letterman's blue grass is a rare (CNPS 2B.3) California native perennial found in southern Sierra Nevada and White and Inyo Mountains in high alpine environments with sandy soil around boulders at elevations above 3,500 meters. Flowering from July to August, this delicate grass produces small, subtle flowers in narrow lanceolate clusters. Growing in dense tufts to just 2 to 9 centimeters tall, it forms compact, soft clumps with fine, soft stems. Its leaves are extremely narrow, between 0.5 to 1.5 millimeters wide, with open sheaths and truncate to acute ligules, typically flat or gently folded. The grass has delicate spikelets with glumes slightly longer than the lowest lemma and glabrous callus.
Identification and appearance
Key characters: 30 sympatric species; distinguished by extreme high elevation and tiny stature
Habitat and range
Habitat: High alpine, in sandy soil around boulders
Elevation: > 3500 m
Outside California: to southwestern Canada, Rocky Mountains south to Colorado
Bloom period
Poa lettermanii blooms Jul-Aug.
Conservation status
CNPS 2B.3
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 lettermanii native to California?
Yes. Poa lettermanii is native to California (recorded as native).
When does Poa lettermanii bloom?
Poa lettermanii blooms Jul-Aug.
What plant family does Poa lettermanii belong to?
Poa lettermanii is in the Poaceae family, genus Poa.
Is Poa lettermanii rare or endangered?
Poa lettermanii carries California Rare Plant Rank 2B.3, state rank S3.
What habitat does Poa lettermanii grow in?
Poa lettermanii grows in High alpine, in sandy soil around boulders.
Related species
Other California species in the same genus, family, or bioregion.
Sources: Jepson eFlora · 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.