Poa trivialis subsp. sylvicola
Rough blue grass
Photo: parent species Poa trivialis · no rights reserved · CC0
Family: Poaceae · Type: Grass
Poa trivialis subsp. sylvicola (Rough blue grass) is a California grass in the Poaceae family, recognized by coastal dune habitat and bead-like stolon swellings.
Rough blue grass is a naturalized perennial found in disturbed coastal dunes below 100 meters elevation. Flowering from February to March, this grass produces delicate light green to greenish-white flower clusters in loose, open panicles. Growing with short stolons that have distinctive bead-like swellings, it forms low-spreading patches in coastal environments. Its leaf sheaths are nearly smooth to moderately rough-textured, with slender blades that spread irregularly across the ground. The grass produces small lemmas with distinctly hairy marginal veins near the base, characteristic of its subtle but unique morphology.
Identification and appearance
Key characters: 24 sympatric species; distinguished by coastal dune habitat and bead-like stolon swellings
Habitat and range
Habitat: Disturbed coastal dunes
Elevation: < 100 m
Outside California: not detected elsewhere in North America, native to southern Europe, north Africa, west Asia
Bloom period
Poa trivialis subsp. sylvicola blooms Feb-Mar.
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
When does Poa trivialis subsp. sylvicola bloom?
Poa trivialis subsp. sylvicola blooms Feb-Mar.
What plant family does Poa trivialis subsp. sylvicola belong to?
Poa trivialis subsp. sylvicola is in the Poaceae family, genus Poa.
What habitat does Poa trivialis subsp. sylvicola grow in?
Poa trivialis subsp. sylvicola grows in Disturbed coastal dunes.
Related species
Other California species in the same genus, family, or bioregion.
- Poa trivialis subsp. trivialis — Rough blue grass
- Poa unilateralis subsp. unilateralis — San francisco blue grass
- Poa wheeleri — Hooker's bluegrass
- Poa abbreviata — Dwarf blue grass
- Poa abbreviata subsp. marshii — Marsh's blue grass
- Poa abbreviata subsp. pattersonii — Patterson's blue grass
- Polypogon australis — Chilean beard grass
Sources: Jepson eFlora · 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.