Poa napensis
Napa blue grass
no rights reserved, uploaded by Scott Yarger · CC0
Family: Poaceae · Type: Grass · Native
Conservation status: CNPS 1B.1 · Endangered
Poa napensis (Napa blue grass) is a native California grass in the Poaceae family, recognized by no sympatric species.
Napa blue grass is a rare (CNPS 1B.1) California native perennial found in southeastern North Coast Ranges near Calistoga, Napa County in low sterile mineralized ground near hot springs at elevations of 100 to 200 meters. Flowering in May, this plant produces pale green to bluish flowers in dense, scabrous spikelets. Growing as a densely tufted grass 30 to 100 centimeters tall with ascending stems, it forms compact clumps with firm, narrow leaves. Its leaf blades are 1 to 3 millimeters wide, folded or tightly rolled, with rough (scabrous) surfaces and ligules 4 to 6 millimeters long. The plant's delicate spikelets are concentrated in the upper half of an open, 5 to 15 centimeter inflorescence, creating a distinctive compact grass structure.
Identification and appearance
Key characters: Geographically isolated; no sympatric species
Habitat and range
Habitat: Low sterile mineralized ground near hot springs
Elevation: 100-200 m
Bloom period
Poa napensis blooms May.
Conservation status
CNPS 1B.1 · 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 napensis native to California?
Yes. Poa napensis is native to California (recorded as native).
When does Poa napensis bloom?
Poa napensis blooms May.
What plant family does Poa napensis belong to?
Poa napensis is in the Poaceae family, genus Poa.
Is Poa napensis rare or endangered?
Poa napensis carries California Rare Plant Rank 1B.1, state rank S1.
What habitat does Poa napensis grow in?
Poa napensis grows in Low sterile mineralized ground near hot springs.
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.