Arnica ×diversifolia Greene (pro sp.) [amplexicaulis or mollis × cordifolia or latifolia]

vernacular rayless arnica — species · Asteraceae

USDA: ARDI7
GBIF: 5405990 syn.
Rank: species

rayless arnica (Arnica ×diversifolia) — Platephotograph · "<a href=""http://www.pwrc.usgs.gov/WLI/"">USDA NRCS Wetland Science Institute</a>."CC BY-NC-SA source · iNaturalist ↗

§2Habit & range

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

§2a

Native status, by region

AK Alaska Native
L48 Lower 48 States Native

§2b

County-level range

· 2 counties across 1 state

Legend Native · 2 Introduced · 0 Both · 0 Hover a county for detail.

§3Cultivation specs · USDA

Recorded by the USDA Plant Materials Program.

§3a

Tolerances

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

§3b

Climate & soil

Cold tolerance: -23 °F minimum
Frost-free days: 125 min.
Precipitation: 12–24 in/yr
pH range: 6.3–7.8
Root depth: 10 in min.
Fertility need: Low
Soil texture: coarse, medium

§3c

Form & growth

Growth form: Rhizomatous
Growth rate: Moderate
Lifespan: Moderate
Mature height: 1.3 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: Summer
Seed abundance: Medium
Seed begins: Summer
Seed ends: Summer
Spread rate: Moderate
Stratify: No
Seeds / lb: 350,000
Propagation: seed, bare root, sprigs

§3e

Use & availability

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

§4Counties, by state

Recorded in 2 counties across 1 state.

Montana view state ↗ 2 N ▾

§5Sources & provenance

USDA PLANTS

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

plants.usda.gov/ARDI7 ↗

GBIF Backbone

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

gbif.org/species/5405990 ↗

Record version

Cached and built locally. Source version on this record:

usda-plants-mt-2026-05-25

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