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Western Wheatgrass

Agropyron smithii (accepted: Elymus smithii) · Poaceae · all Agropyron records

Your local evidence lens

Separate evidence questions, never one approval badge

Set a ZIP to compare this record with state distribution, native range, USDA hardiness, and invasive records.

A genus split is not a placement verdict. Set a ZIP to read the local documented split.

1. Fire evidence and conditions

Fire evidence: Fire-resistant — location does not change the cited classification.
Fire-performance conditions: No test or rating condition is normalized.
Fire ecology context: No section-reviewed fire-ecology context is normalized.
Placement evidence: 2 source placement records; source schemes remain separate.
Evidence regions: Arizona above 3,000 feet / interior Southwest; British Columbia; Global; Nevada / Great Basin; Northern Nevada / Great Basin; Utah / Intermountain West; southern Idaho / Intermountain
Maintenance: No sourced horticultural maintenance assertion is normalized; fire-test conditions do not supply maintenance advice.

Typed publication scope: 4 scopes across 4 cited fire sources

Fire Resistance of Plants Master Database · Official scoped edition
- Southern Idaho (ID footprint); partial normalized coverage · 2013-11-08
  The official database labels itself "For Southern Idaho" and describes Idaho residents at the urban-rangeland interface. FireApproved publishes 419 existing plant owners that cite its scored rows. This bounded Southern Idaho scope is regional context, not statewide coverage or a conclusion that the score transfers unchanged to every Idaho site.
FIREWISE Plant Materials for 3,000 ft. and Higher Elevations (AZ1289) · Official scoped edition
- Arizona at or above 3,000 feet (AZ footprint); partial normalized coverage · 2011-12-01
  AZ1289 is explicitly limited to Arizona elevations of 3,000 feet and higher. FireApproved publishes 69 exact owners as regional Arizona context, retaining every water and elevation condition. It is never promoted to statewide low-desert guidance or an independent Tier 1 vote.
A Compilation of Good Plant Choices for Nevada's High Fire Hazard Areas (SP-05-16) · Official scoped edition
- NV; partial normalized coverage · 2005-01-01
  University of Nevada Cooperative Extension compiled plants suited to Nevada climate zones and reported favorably by at least two upstream firewise lists. FireApproved publishes 126 exact source owners at Nevada publication scope. The source explicitly makes no independent flammability determination, so these rows remain corroborative.
Firewise Plants for Utah Landscapes (NR/FF/002) · Official scoped edition
- UT; partial normalized coverage · 2005-02-01
  Utah State University Extension states that this fact sheet selects examples for Utah landscapes and that they require proper placement and maintenance. FireApproved publishes 83 exact source owners at Utah publication scope. The table is not a site-specific planting clearance.

2. Why this plant is relevant here

State distribution: Documented in AK, AR, AZ, CA, CO, GA, IA, ID, IL, IN, KS, KY, MA, MI, MN, MO, MT, ND, NE, NH, NM, NV, NY, OH, OK, OR, SD, TN, TX, UT, WA, WI, WY.
Native range: No current cited or legacy state native range is normalized.
Introduced / established: No introduced or established row is normalized; that does not prove native status.
USDA hardiness: Documented minimum 4a; no upper limit is documented.

3. Legal, ecological, and broader status

Legal-list status: Set a location for an exact legal-list result; source silence is not clearance.
Seed-list status: Set a location to compare the separate state noxious-weed seed layer.
Reported invasive here: No ecological invasive report is normalized; that does not prove noninvasiveness.
Broader regional context: Aggregate AK, HI, and L48 evidence is shown only as regional context, never as an exact-state finding.
Federal context: Federal designations remain separate from state legal-list results.

How to read this page

The status above is computed from the cited rows below: independent recommendations can support a fire-resistant result, an avoid row can produce keep-away, and disagreement stays visible as conflict. Placement notes preserve each source’s own scheme rather than translating unlike rules into one scale. This is evidence about a plant, not permission to plant it in every part of the defensible space; Zone 0 remains noncombustible.

Western Wheatgrass (Agropyron smithii) — Photo: (c) Matt Lavin, some rights reserved (CC BY) (CC BY), via iNaturalist. Species-typical, not necessarily this cultivar.

Form: grass
USDA hardiness: Minimum 4a; upper limit not documented
Mature height: ~2 ft
Water need: moderate
Grows in: AK, AR, AZ, CA, CO, GA, IA, ID +25
Rated in: Arizona above 3,000 feet / interior Southwest; British Columbia; Global; Nevada / Great Basin +3
Family: Poaceae
Evidence: 10 cited sources

Plant hardiness evidence

These values describe the plant source. Your ZIP zone comes from the separate 2023 USDA Plant Hardiness Zone Map. Whole-zone values stay whole-zone, and a single unresolved value is not treated as a tolerance range. Different source boundaries stay separate: overlapping statements are compared independently, while only ranges with no shared zone are called a conflict.

USDA PLANTS Database — Plant Characteristics · record PASM · PLANTS Help Document 2022; characteristics cache retrieved 2026-08-23 · as of 2026-08-26

Minimum 4a · no upper limit documented · half zone precision · derived containing band

Exact source measurement: -28°F; mapped only to its containing half-zone.

Source taxon: Agropyron smithii · source identifier match.

Source location: PlantCharacteristics record 24416, Temperature, Minimum (°F).

Where its sources say to plant it

Placement rules below use each source's own distances or named zones, tied to its rating. They are not interchangeable with the directory's current Zone 0 guidance.

Fire Resistance of Plants Master Database: plantable at 70' from home [Idaho minimum planting distance] (mid-scale rating)
Greenstrips: Another Tool to Manage Wildfire: common perennial plant used in a maintained northern Nevada greenstrip [unr-fs-97-36-greenstrip] (with its recommendation)

The evidence

Grouped by what each source concluded. Primary evidence rated the plant itself (a lab, field program, or original curation); corroboration compiled or republished another source's rating and resolves to its root lineage.

Mid-scale / conditional (1)

Fire Resistance of Plants Master Database — Idaho Firewise (BLM + College of Western Idaho + Idaho Botanical Garden) · original source Primary evidence Field program lineage: idaho-tree

“fire-resistance score 4 of 10” · score 4 (idaho-0-10)

Listed without a rating (4)

FLAMITS: FLAMmability plant traiTS database — Dryad / Global Ecology and Biogeography · Dryad version 9 · original source Corroboration Trait database lineage: meta-aggregator

4 cited rows from this source; its identity, lineage and tier are stated once.
- “time to flaming (s): 3.398” · score 3.398 (FLAMITS — time to flaming (s))
  
  FLAMITS record 17366; Ignitability measurement; plant part whole plant; fuel live; predrying yes; device burning bench; site Gao2018-1; sampling june to august 2016. Primary study Gao2018: Gao, X., & Schwilk, D. W. (2018). Grass Canopy Architecture Influences Temperature Exposure at Soil Surface. Fire 1, 35.
- “flaming duration (s): 51.96666667” · score 51.96666667 (FLAMITS — flaming duration (s))
  
  FLAMITS record 17367; Sustainability measurement; plant part whole plant; fuel live; predrying yes; device burning bench; site Gao2018-1; sampling june to august 2016. Primary study Gao2018: Gao, X., & Schwilk, D. W. (2018). Grass Canopy Architecture Influences Temperature Exposure at Soil Surface. Fire 1, 35.
- “smouldering duration (s): 71.386” · score 71.386 (FLAMITS — smouldering duration (s))
  
  FLAMITS record 17368; Sustainability measurement; plant part whole plant; fuel live; predrying yes; device burning bench; site Gao2018-1; sampling june to august 2016. Primary study Gao2018: Gao, X., & Schwilk, D. W. (2018). Grass Canopy Architecture Influences Temperature Exposure at Soil Surface. Fire 1, 35.
- “flame height (cm): 94.93333333” · score 94.93333333 (FLAMITS — flame height (cm))
  
  FLAMITS record 17369; Combustibility measurement; plant part whole plant; fuel live; predrying yes; device burning bench; site Gao2018-1; sampling june to august 2016. Primary study Gao2018: Gao, X., & Schwilk, D. W. (2018). Grass Canopy Architecture Influences Temperature Exposure at Soil Surface. Fire 1, 35.

Last verified 2026-08-23. JSON (CC BY 4.0)

Profiles: USDA PLANTS · GBIF · iNaturalist · Wikidata · ITIS

Agropyron smithii (Western Wheatgrass). FireApproved. https://fireapproved.com/plants/agropyron-smithii/. Last verified 2026-08-23.