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Poaceae family

Rattlesnake Brome Bromus briziformis

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

Rattlesnake Brome is an introduced annual grass, found in Alaska, Canada, and the lower 48 states. It grows to 1.6 ft and blooms May in part shade – shade, with brown fruit.

More about this plant

Bromus briziformis is a species of brome grass known by the common name rattlesnake brome. The specific epithet briziformis comes from the resemblance of the grass to grasses of the genus Briza, particularly Briza maxima. The common name is derived from the resemblance of the spikelets to the rattles of rattlesnakes. The grass has a diploid number of 14. Wikipedia →

⚠ Invasive here — plant a native instead USDA + GBIF

Rattlesnake Brome is flagged invasive in the U.S. These natives fill a similar niche — same growth habit, bloom season, height, and region — so you keep the look and feed local wildlife instead of spreading a problem.

Threadleaf Sedge
Native
Threadleaf Sedge
Carex filifolia
●●●○○
Slender Spikerush
Native
Slender Spikerush
Eleocharis tenuis
●●●○○
Plains Muhly
Native
Plains Muhly
Muhlenbergia cuspidata
●○○○○
Indian Ricegrass
Native
Indian Ricegrass
Achnatherum hymenoides
●○○○○
Matched on growth habit · bloom months · mature height · shared U.S. range (USDA + GBIF) — a starting point, not a prescription.

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
Low moisture
Soil pH
5.3–7.2
Fertility need
Medium
Adapts to
Coarse (sandy), Medium (loam)
Hardiness
USDA zone 12+
Size & form
Sources · Size & form
USDA PLANTS (DwCA, Zenodo 17903503) — Height, Mature — Height
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
TRY Plant Trait Database (CC BY 4.0) · USDA PLANTS — Foliage
USDA PLANTS (DwCA, Zenodo 17903503) — Fruit/Seed Color / Fruit Persistence — Fruit
Height
1.6 ft
Spread
None — clumping
Growth rate
Rapid
Growth form
Bunch
Lifespan
Annual
Foliage
Broadleaf · medium texture
Active growth
Spring & summer
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
Seed
Seed starting
No stratification needed
Seeds ripen
Spring – Summer seed-collection / harvest window
In the trade
No known commercial source
Deer browsing
Low often deer-resistant
Resprouts if cut
No
Herb layer — Sits in the herb 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 ~12 caterpillar species

Bromus supports ~12 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 moderate genus.

Recorded feeding on Bromus in North America, including:

Agrotis orthogonia · Pale Western Cutworm Apamea finitima · owlet moth Cisseps fulvicollis · Yellow-Collared Scape Moth Cosmiotes illectella · grass-miner moth Ctenucha virginica · Virginia Ctenucha Faronta diffusa · owlet moth
+ 8 more species →
Gonioterma mistrella · concealer moth Hemileuca oliviae · giant silk moth Hesperia comma · Silver-Spotted Skipper Hesperia juba · Juba Skipper Hesperia ottoe · Ottoe Skipper Leucania insueta · owlet moth Leucania multilinea · Many-Lined Wainscot Leucania phragmitidicola · Phragmites Wainscot
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.
How we know this (1) Methods & honest limits
Climate niche (heat tolerance & native rainfall) Derived

We take the plant’s U.S. county range and look up each county’s long-term climate, then summarise: native rainfall = the median annual rainfall across its counties; heat tolerance = the warm end (90th percentile) of average temperature across its range (mirroring how our cold-hardiness floor uses an extreme). Counties + medians blunt the roadside/observer bias that makes point-level climate unreliable. Needs at least five placeable counties.

Honest limits: A realized, sampling-biased niche (where it has been recorded, not its physiological optimum), and county climate is coarse — large Western counties span deserts and mountains. Derived guide, never a measured fact.

Realized-niche / climate-envelope approach (Pearson & Dawson 2003; Soberón 2007). Climate: NOAA NCEI nClimDiv county normals (1991–2020).
Derived values are computed from open data by a published method — labelled, cited, and never shown as a direct observation. Full methodology →
Sources for this entry (28) 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)
[17] Invasive / introduced status — US-RIIS v2.0 (USGS)
[18] Wetland indicator — USACE National Wetland Plant List (2022)
[20] Description — Wikipedia (CC BY-SA)
[21] Ecological value — Warren II 2026 (CC0) · Tallamy host-use counts
[23] Functional traits — TRY Plant Trait Database (CC BY 4.0)
[24] Climate niche — Derived — realized climate niche from U.S. county occurrences (GBIF) × NOAA NCEI county climate normals 1991–2020 (public domain)
[26] Caterpillar host count — Warren II 2026 (Dryad, CC0) · Tallamy host-use counts
[27] Caterpillar species — NHM HOSTS (CC0)
[28] County range — GBIF Open Data — open-licensed occurrences (CC0/CC-BY) → county
Spot an error or have a better photo? Every field links to its source, and the whole dataset is open.
Cite this page Open data, please attribute

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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