Pascopyrum smithii (Rydb.) Á. Löve

vernacular western wheatgrass — species · Poaceae

USDA: PASM
GBIF: 5290148 syn.
Rank: species

western wheatgrass (Pascopyrum smithii) — Platephotograph · lholzbaughCC BY-NC source · iNaturalist ↗

§2Habit & range

Growth habit: Graminoid
Duration: Perennial
Group: Monocot
Family: Poaceae Barnhart
Genus: Pascopyrum

§2a

Native status, by region

AK Alaska Introduced
CAN Canada Native
L48 Lower 48 States Native

§2b

County-level range

· 18 counties across 1 state

Legend Native · 18 Introduced · 0 Both · 0 Hover a county for detail.

§3Cultivation specs · USDA

Recorded by the USDA Plant Materials Program.

§3a

Tolerances

Drought: High
Shade: High
Moisture use: Medium
Fire: High
Salinity: High
Anaerobic: Medium
CaCO₃: High
Hedging: None

§3b

Climate & soil

Cold tolerance: -43 °F minimum
Frost-free days: 90 min.
Precipitation: 8–36 in/yr
pH range: 4.5–9
Root depth: 20 in min.
Fertility need: Medium
Soil texture: medium, fine

§3c

Form & growth

Growth form: Rhizomatous
Growth rate: Rapid
Lifespan: Long
Mature height: 2 ft
Foliage texture: Medium
Foliage colour: Gray-Green
Porosity (summer): Moderate
Porosity (winter): Porous
Flower colour: Yellow
Fruit colour: Brown
Fire resistant: No
N fixation: None
Toxicity: None

§3d

Reproduction

Bloom period: Mid Summer
Seed abundance: Low
Seed begins: Summer
Seed ends: Fall
Spread rate: Slow
Stratify: No
Seeds / lb: 113,840
Propagation: seed

§3e

Use & availability

Commercial availability: Routinely Available
Nursery stock: No
Browse palatability: Medium
Graze palatability: Medium
Palatable, human: No
Protein potential: Medium
Lumber: No
Christmas tree: No

§4Counties, by state

Recorded in 18 counties across 1 state.

Montana view state ↗ 18 N ▾

§5Sources & provenance

USDA PLANTS

Symbol, taxonomy, distribution, cultivation specs, native status. Public domain.

plants.usda.gov/PASM ↗

GBIF Backbone

Canonical taxonomic identity, synonym resolution, cross-refs. CC0.

gbif.org/species/5290148 ↗

Record version

Cached and built locally. Source version on this record:

usda-plants-mt-2026-05-25

fetched 2026-05-25T18:27:19Z