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Pictured: Leymus mollis — the species. This subspecies isn’t separately illustrated.
Poaceae family

American Dunegrass (subsp. mollis) Leymus mollis subsp. mollis subspecies

Native
Deer-resistant — Low palatability to browsing deer. Usually passed over, but no plant is truly deer-proof when food is scarce.

American Dunegrass (subsp. mollis) is a perennial grass native to Alaska, Canada, and Greenland. It grows to 4 ft and blooms May in part shade – shade, with brown fruit.

Growing & care

USDA PLANTS · TRY
Conditions
Sources · Conditions
USDA PLANTS — Sun · Soil & moisture
USDA — SoilPH — Soil pH
USDA PLANTS (DwCA, Zenodo 17903503) — Fertility Requirement / Soil Adaptation — Fertility need · Adapts to
USDA — Temp-Min °F — Hardiness
Sun
Part shade – shade
Soil & moisture
Medium moisture
Soil pH
6–8
Fertility need
Low
Adapts to
Coarse (sandy)
Hardiness
USDA zone 8+
Size & form
Sources · Size & form
USDA PLANTS (DwCA, Zenodo 17903503) — Height, Mature — Height
USDA PLANTS (DwCA, Zenodo 17903503) — Planting Density (per acre) — Spacing
USDA PLANTS (DwCA, Zenodo 17903503) — Growth Rate / Spread / Growth Form / Lifespan / Active Growth Period / Seed Period — Spread · Growth rate · Growth form · Active growth
USDA PLANTS — Lifespan
USDA PLANTS — FoliageTexture — Foliage
USDA PLANTS (DwCA, Zenodo 17903503) — Fruit/Seed Color / Fruit Persistence — Fruit
Height
4 ft
Spacing
2–4 ft apart from USDA planting density
Spread
Moderate
Growth rate
Rapid
Growth form
Rhizomatous
Lifespan
Perennial · long-lived
Foliage
coarse texture
Active growth
Spring & autumn
Fruit
Brown
In the garden
Sources · In the garden
USDA PLANTS (DwCA, Zenodo 17903503) — Propagation Method / Commercial Availability — Propagate by · In the trade
USDA PLANTS (DwCA, Zenodo 17903503) — Germination (cold stratification) — Seed starting
USDA PLANTS — Seed Period — Seeds ripen
USDA PLANTS (DwCA, Zenodo 17903503) — Foliage Texture / Browse Palatability / Resprout — Deer browsing · Resprouts if cut
Propagate by
Sprigs
Seed starting
No stratification needed
Seeds ripen
Summer – Autumn seed-collection / harvest window
In the trade
Routinely available
Deer browsing
Low often deer-resistant
Resprouts if cut
No
Shrub layer — Sits in the shrub of a layered food forest or polyculture.Open guide →
derived roles
The garden year bloom → fruit → fall colour
J
F
M
A
M
J
J
A
S
O
N
D
Bloom
Bloom (the flower's colour)
Bloom · May — USDA PLANTS (DwCA, Zenodo 17903503) — BloomPeriod
When to sow · for your area

Sow timing keys off your local last- and first-frost dates.

Species characteristics from USDA PLANTS (public domain) + TRY (CC BY) — general guidance, not a guarantee for your exact site. Deer "browsing" is documented palatability, not a deer-proof claim.

Wildlife & pollinators

How pollinator value is scored →
❧ Caterpillar hosts ~3 caterpillar species

Leymus supports ~3 caterpillar species.

Native butterfly & moth caterpillars are the base of the terrestrial food web — most songbirds rear their young almost entirely on them. As a host for native Lepidoptera this is a modest genus.

Recorded feeding on Leymus in North America, including:

Apamea cuculliformis · owlet moth Benjaminiola colorada · owlet moth Ctenucha brunnea · Brown Ctenucha Mammifrontia rileyi · owlet moth Mesapamea stipata · owlet moth Ochlodes sylvanoides · Woodland Skipper
+ 1 more species →
Pseudaletia unipuncta · White-Speck
Keystone count (genus-level) from Warren II 2026 (CC0) · Tallamy host-use records. Named species (a documented Nearctic sample, not exhaustive) from NHM HOSTS (CC0).
Species thumbnails re-hosted from iNaturalist — Creative Commons, credited per image (hover for credit). Click any species to see it on iNaturalist. Not exhaustive; many taxa have no openly-licensed photo yet.
Sources for this entry (24) Open & cited
[01] Scientific name & family — USDA PLANTS (DwCA, Zenodo 17903503)
[02] Growth habit & duration — USDA PLANTS (DwCA, Zenodo 17903503)
[03] Native status & distribution — USDA PLANTS (DwCA, Zenodo 17903503)
[04] Common name — USDA PLANTS (via GBIF)
[18] Invasive / introduced status — USDA PLANTS (DwCA, Zenodo 17903503) — native status
[19] Ecological value — Warren II 2026 (CC0) · Tallamy host-use counts
[20] Conservation rank — NatureServe Explorer (CC BY)
[22] Caterpillar host count — Warren II 2026 (Dryad, CC0) · Tallamy host-use counts
[23] Caterpillar species — NHM HOSTS (CC0)
Spot an error or have a better photo? Every field links to its source, and the whole dataset is open.
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PlantKey’s data is open under CC BY-SA 4.0 — free to reuse and adapt, with attribution and the same licence. Photos keep their own per-image licence + credit (see Sources above).

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