Calamagrostis breviligulata subsp. breviligulata
American beachgrass
Family: Poaceae (Gramineae) · Not Native
Calamagrostis breviligulata subsp. breviligulata (American beachgrass) is a non-native California plant in the Poaceae (Gramineae) family, recognized by Non-native dune grass; SHORT truncate ligule (1--4.6 mm); dense cylindric panicle, strongly rhizomatous.
American beachgrass is a non-native grass found in the North Coast, northern Central Coast, and South Coast bioregions on beaches and coastal sand dunes at elevations below 10 meters. Flowering from July to September, it spreads by rhizomes with stems 5 to 13 decimeters tall and produces a densely cylindric inflorescence 10 to 40 centimeters long with strongly ascending branches, flat to inrolled leaf blades 4 to 8 millimeters wide, and awnless lemmas.
Identification and appearance
Key characters: Non-native dune grass; SHORT truncate ligule (1--4.6 mm); dense cylindric panicle, strongly rhizomatous
Habitat and range
Habitat: Beaches, coastal sand dunes
Elevation: < 10 m
Outside California: native to eastern North America, common on shores of the Great Lakes
Bloom period
Calamagrostis breviligulata subsp. breviligulata blooms July--September.
How to tell it apart
vs Leymus: Leymus has spike-like inflorescences; Calamagrostis has open, branching panicles.; vs Koeleria: Koeleria has dense spike-like panicles; Calamagrostis panicles are loose and open.; vs Holcus: Holcus has velvety-hairy spikelets; Calamagrostis has silky basal hairs only.; vs Muhlenbergia: Calamagrostis spikelets are 2-4mm with awns; Muhlenbergia often larger without prominent awns.; vs Spinifex: Spinifex forms spiny seed heads on beaches; Calamagrostis has soft panicles in mountains.
Frequently asked questions
Is Calamagrostis breviligulata subsp. breviligulata native to California?
No. Calamagrostis breviligulata subsp. breviligulata is not native to California (recorded as not native).
When does Calamagrostis breviligulata subsp. breviligulata bloom?
Calamagrostis breviligulata subsp. breviligulata blooms July--September.
What plant family does Calamagrostis breviligulata subsp. breviligulata belong to?
Calamagrostis breviligulata subsp. breviligulata is in the Poaceae (Gramineae) family, genus Calamagrostis.
What habitat does Calamagrostis breviligulata subsp. breviligulata grow in?
Calamagrostis breviligulata subsp. breviligulata grows in Beaches, coastal sand dunes.
Related species
Other California species in the same genus, family, or bioregion.
- Calamagrostis breweri — Short hair reed grass
- Calamagrostis canadensis — Bluejoint reedgrass
- Calamagrostis canadensis var. canadensis — Bluejoint reed grass
- Calamagrostis canadensis var. langsdorffii
- Calamagrostis foliosa — Leafy reed grass
- Calamagrostis koelerioides — Dense-pine reed grass
- Anatherum eremicum — Southwestern bushy bluestem
- Anatherum virginicum
- Anatherum virginicum var. virginicum — Broomsedge bluestem
- Brachypodium hybridum — Hybrid falsebrome
Sources: Jepson eFlora
Last updated 2026-09-30
Data from The California Species Project — 14,000+ California species with verified data from CNPS, CDFW, USFWS, Cal-IPC, and more.