Oxytropis lambertii Pursh

vernacular purple locoweed — species · Fabaceae

USDA: OXLA3
GBIF: 5360970
Rank: species

purple locoweed (Oxytropis lambertii) — Platephotograph · rochkie source · iNaturalist ↗

§2Habit & range

Growth habit: Forb/herb
Duration: Perennial
Group: Dicot
Family: Fabaceae Lindl.
Genus: Oxytropis

§2a

Native status, by region

CAN Canada Native
L48 Lower 48 States Native

§2b

County-level range

· 23 counties across 1 state

Legend Native · 23 Introduced · 0 Both · 0 Hover a county for detail.

§3Cultivation specs · USDA

Recorded by the USDA Plant Materials Program.

§3a

Tolerances

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

§3b

Climate & soil

Cold tolerance: -38 °F minimum
Frost-free days: 90 min.
Precipitation: 16–24 in/yr
pH range: 6.4–9
Root depth: 10 in min.
Fertility need: Low
Soil texture: coarse, medium

§3c

Form & growth

Growth form: Single Crown
Growth rate: Moderate
Lifespan: Moderate
Mature height: 1.4 ft
Foliage texture: Medium
Foliage colour: Gray-Green
Porosity (summer): Porous
Porosity (winter): Porous
Flower colour: Red
Fruit colour: Brown
Fire resistant: No
N fixation: Low
Toxicity: Severe

§3d

Reproduction

Bloom period: Mid Spring
Seed abundance: Medium
Seed begins: Spring
Seed ends: Summer
Spread rate: Slow
Stratify: No
Seeds / lb: 209,000
Propagation: seed

§3e

Use & availability

Commercial availability: No Known Source
Nursery stock: No
Palatable, human: No
Protein potential: Low
Lumber: No
Christmas tree: No

§4Counties, by state

Recorded in 23 counties across 1 state.

§5Sources & provenance

USDA PLANTS

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

plants.usda.gov/OXLA3 ↗

GBIF Backbone

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

gbif.org/species/5360970 ↗

Record version

Cached and built locally. Source version on this record:

usda-plants-mt-2026-05-25

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