Elymus mollis subsp. mollis
American dune grass, sea lyme grass, American Lyme Grass
(c) Matt Lavin, some rights reserved (CC BY-SA) · licence
Family: Poaceae · Type: Grass · Native
Elymus mollis subsp. mollis (American dune grass) is a native California grass in the Poaceae family, recognized by habitat specialization on beaches with distinctive hairy stems and lemmas.
American dune grass is a California native perennial found in northern coastal and central coastal bioregions on sandy beaches at elevations generally below 10 meters. Flowering from May to July, this plant produces pale green to white flowers in elongated grass heads 12 to 34 centimeters long. Growing with robust rhizomatous stems 50 to 170 centimeters tall that are densely hairy near the flowering stalks, it spreads extensively across beach environments. Its leaves are long and narrow, measuring 10 to 95 centimeters in length and 3 to 15 millimeters wide, with slightly rough upper surfaces. The plant develops distinctive grass spikelets with hairy lance-shaped glumes and densely hairy lemmas that are sharp or awn-tipped.
Identification and appearance
Key characters: 12 sympatric species; habitat specialization on beaches with distinctive hairy stems and lemmas
Habitat and range
Habitat: Sandy beaches
Elevation: generally < 10 m
California counties: Humboldt, Mendocino, San Luis Obispo, Monterey, San Mateo
Outside California: to Alaska, Asia
Bloom period
Elymus mollis subsp. mollis blooms May-Jul.
How to tell it apart
vs Hordeum: Elymus has rounded glume backs; Hordeum has all glumes narrow and bristle-like.; vs Leymus: Elymus has 2-8 spikelets per node; Leymus has just 1-2 spikelets per node.; vs Taeniatherum: Elymus is perennial with robust growth; Taeniatherum is a weedy annual with very long awns.; vs Lolium: Elymus shows multiple spikelets per node; Lolium has single spikelets edgewise to the stem.; vs Thinopyrum: Elymus has prominent auricles; Thinopyrum typically lacks auricles or has very small ones.
Frequently asked questions
Is Elymus mollis subsp. mollis native to California?
Yes. Elymus mollis subsp. mollis is native to California (recorded as native).
When does Elymus mollis subsp. mollis bloom?
Elymus mollis subsp. mollis blooms May-Jul.
Where in California does Elymus mollis subsp. mollis grow?
Elymus mollis subsp. mollis occurs in Humboldt, Mendocino, San Luis Obispo, Monterey, San Mateo, at elevations of generally < 10 m.
What plant family does Elymus mollis subsp. mollis belong to?
Elymus mollis subsp. mollis is in the Poaceae family, genus Elymus.
What habitat does Elymus mollis subsp. mollis grow in?
Elymus mollis subsp. mollis grows in Sandy beaches.
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.