Flower profile
Heartleaf arnica
Arnica cordifolia
Heartleaf arnica (Arnica cordifolia) is a flowering plant in the Asteraceae family, native in the lower 48 states, blooming mostly May–July across the U.S.
Heartleaf arnica is a wildflower that USDA PLANTS lists as native in the lower 48 states. It's on our flower lists for 2 states, and across the U.S. it's most often seen in bloom in May–July.
*iNaturalist research-grade observations, as of October 17, 2026.
Quick look
Arnica cordifolia is a species of arnica in the sunflower family, known by the common name heartleaf arnica. It is native to western North America.
- It belongs to the Asteraceae family. iNaturalist
- USDA PLANTS describes it as an herb (forb) with a perennial life cycle. USDA PLANTS
- USDA PLANTS lists it as native in the lower 48 states and records it in 15 states. USDA PLANTS
- NatureServe lists it as native to Montana and Wyoming. NatureServe
- In Montana, most iNaturalist sightings of it in flower come in May–June. iNaturalist
- USDA PLANTS lists its flower color as yellow. USDA PLANTS
- USDA PLANTS gives its bloom period as late spring. USDA PLANTS
- USDA PLANTS lists a mature height of about 1.5 ft. USDA PLANTS
- iNaturalist has 872 research-grade sightings of it in Montana, ranking #40 among the 128 flowers on our Montana list. iNaturalist
- iNaturalist has 303 research-grade sightings of it in Wyoming, ranking #95 among the 113 flowers on our Wyoming list. iNaturalist
When does it bloom?
Conservation status
- Federal (U.S. ESA)
- Not listed Not listed under the Endangered Species Act. USFWS ECOS does track it with the label “Resolved Taxon,” which is informal and gives no legal protection. USFWS ECOS
- NatureServe global
- G5 Secure worldwide. NatureServe
- Montana
- No list Montana has no state law listing endangered or threatened plants, so we show NatureServe's Montana ranks instead. NatureServe: S5, secure in Montana.
- Wyoming
- No list Wyoming has no state law listing endangered or threatened plants, so we show NatureServe's Wyoming ranks instead. NatureServe: S5, secure in Wyoming.
- Rare elsewhere
- Other states where NatureServe ranks it rare or missing: MI (S1), NE (S1). (S1 critically imperiled, S2 imperiled, SH possibly extirpated, SX presumed extirpated.)
Checked October 17, 2026. Rankings and lists can change, so follow the links for the latest.
Can you eat it?
None of the sources we checked (NC State Extension (no page for this plant), USDA PLANTS) say whether it's edible or poisonous for people.
It isn't on the ASPCA plant list.
🌿 Never eat a wild plant unless you're certain of its ID; this isn't medical advice. Worried about a person? Call Poison Control at 1-800-222-1222. Worried about a pet? Call your vet.
Where does it grow?
USDA PLANTS records heartleaf arnica in 15 states.
recorded by USDA PLANTS on our state lists not recorded
See the full list of states
Alaska, Arizona, California, Colorado, Idaho, Michigan, Montana, Nevada, New Mexico, North Dakota, Oregon, South Dakota, Utah, Washington, Wyoming.
Montana counties with USDA records: Beaverhead, Broadwater, Carbon, Cascade, Deer Lodge, Flathead, Gallatin, Glacier, Granite, Hill, Jefferson, Judith Basin, Lake, Lewis and Clark, Madison, Meagher, Missoula, Park, Phillips, Powell, Rosebud, Silver Bow, Stillwater.
Wyoming counties with USDA records: Albany, Big Horn, Campbell, Carbon, Converse, Crook, Fremont, Hot Springs, Johnson, Laramie, Lincoln, Natrona, Park, Sheridan, Sublette, Sweetwater, Teton, Uinta, Washakie, Weston.
Growing conditions
USDA PLANTS gives Heartleaf arnica a low shade tolerance, low drought tolerance and high moisture use. It is rated for soil pH 6.0 to 8.0 and winter lows down to -28 °F.
- Shade tolerance
- Low
- Drought tolerance
- Low
- Moisture use
- High
- Soil textures it is adapted to
- coarse, medium, fine
- Soil pH range
- 6.0 to 8.0
- Minimum temperature tolerated
- -28 °F
- Frost-free days needed (minimum)
- 130
- Annual precipitation range
- 10 to 35 inches
- Minimum root depth
- 6 inches
- Salinity tolerance
- None
- Fertility requirement
- Medium
- Growth rate
- Rapid
- Lifespan
- Short
- Active growth period
- Spring and Summer
- Fruit or seed
- White · Summer to Fall
- Can be propagated by
- bare root, container, corm, cuttings, seed, sprigs
- Commercial availability
- Contracting Only
From the USDA PLANTS characteristics data for ARCO9. USDA ratings are general guidance for the species, not a guarantee for your garden.
Names, range and relatives
Native status by region (USDA PLANTS): Alaska: Native; Canada: Native; Lower 48 states: Native.
Other scientific names (synonyms in USDA PLANTS): Arnica hardinae, Arnica humilis, Arnica paniculata, Arnica whitneyi.
County records: USDA PLANTS lists it in 226 counties across 15 states; the most are in Colorado (36), Idaho (34), Utah (29).
More from the Asteraceae family (212 on Bloomipedia; most observed first): Common yarrow, Goldenrods, White snakeroot, Sunflowers, Chicory, Black-eyed Susan, Bull thistle, Common dandelion.
More Montana flowers
Sources
- USDA, NRCS. PLANTS Database, profile ARCO9.
- iNaturalist, Arnica cordifolia: taxonomy, research-grade observation counts and “Flowering” annotations, retrieved October 17, 2026.
- Wikipedia, Arnica cordifolia (lead quoted under CC BY-SA 4.0).
- Montana: Montana noxious weed list (Admin. R. Mont. 4.5.206–4.5.210).
- Wyoming: Wyoming state designated noxious weeds (W.S. 11-5-102(a)(xi)), as listed by the Wyoming Weed & Pest Council.
- USFWS, ECOS species database (ESA listing check), October 17, 2026.
- NatureServe Explorer, Arnica cordifolia (global and state ranks).
- Edibility and toxicity: no source found (marked "not well documented").
- Photo: Daughter Dad via iNaturalist · CC BY 4.0 · resized.