Arnica longifolia D.C. Eaton

vernacular spearleaf arnica — species · Asteraceae

USDA: ARLO6
GBIF: 5405970
Rank: species

spearleaf arnica (Arnica longifolia) — Platephotograph · Jim MorefieldCC BY source · iNaturalist ↗

§2Habit & range

Growth habit: Forb/herb
Duration: Perennial
Group: Dicot
Family: Asteraceae Bercht. & J. Presl
Genus: Arnica

§2a

Native status, by region

CAN Canada Native
L48 Lower 48 States Native

§2b

County-level range

· 5 counties across 1 state

Legend Native · 5 Introduced · 0 Both · 0 Hover a county for detail.

§3Cultivation specs · USDA

Recorded by the USDA Plant Materials Program.

§3a

Tolerances

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

§3b

Climate & soil

Cold tolerance: -33 °F minimum
Frost-free days: 100 min.
Precipitation: 16–60 in/yr
pH range: 6–8
Root depth: 10 in min.
Fertility need: Medium
Soil texture: coarse, medium, fine

§3c

Form & growth

Growth form: Bunch
Growth rate: Moderate
Lifespan: Moderate
Mature height: 2 ft
Foliage texture: Coarse
Foliage colour: Green
Porosity (summer): Porous
Porosity (winter): Porous
Flower colour: Yellow
Fruit colour: Brown
Fire resistant: No
N fixation: None
Toxicity: None

§3d

Reproduction

Bloom period: Early Summer
Seed abundance: Medium
Seed begins: Summer
Seed ends: Summer
Spread rate: Slow
Stratify: No
Seeds / lb: 450,000
Propagation: seed

§3e

Use & availability

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

§4Counties, by state

Recorded in 5 counties across 1 state.

Montana view state ↗ 5 N ▾

§5Sources & provenance

USDA PLANTS

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

plants.usda.gov/ARLO6 ↗

GBIF Backbone

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

gbif.org/species/5405970 ↗

Record version

Cached and built locally. Source version on this record:

usda-plants-mt-2026-05-26

fetched 2026-05-26T05:06:36Z