Arnica cordifolia
Heart-leaved arnica
Image of Arnica cordifolia

Photo by Susan R. Crispin 

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Key Characteristics

Small perennial forb of the Keweenaw Peninsula; basal leaves heart-shaped, dentate, large (10 cm long), stem leaves opposite; flowers sunflower-like, 6-8 cm wide.

Status and Rank

  • State Status: E
  • State Rank: S1
  • Global Rank: G5

Occurrences

County NameNumber of OccurrencesYear Last Observed
Keweenaw112014
Distribution map for Arnica cordifolia

Updated 1/31/2017. Information is summarized from MNFI's database of rare species and community occurrences. Data may not reflect true distribution since much of the state has not been thoroughly surveyed.

Habitat

Colonies occur in circumneutral, gravelly clay loam in rocky, second-growth mixed forests.

Natural Community Types

Methodology

For each species, lists of natural communities were derived from review of the nearly 6,500 element occurrences in the MNFI database, in addition to herbarium label data for some taxa. In most cases, at least one specimen record exists for each listed natural community. For certain taxa, especially poorly collected or extirpated species of prairie and savanna habitats, natural community lists were derived from inferences from collection sites and habitat preferences in immediately adjacent states (particularly Indiana and Illinois). Natural communities are not listed for those species documented only from altered or ruderal habitats in Michigan, especially for taxa that occur in a variety of habitats outside of the state.

Natural communities are not listed in order of frequency of occurrence, but are rather derived from the full set of natural communities, organized by Ecological Group. In many cases, the general habitat descriptions should provide greater clarity and direction to the surveyor. In future versions of the Rare Species Explorer, we hope to incorporate natural community fidelity ranks for each taxon.

Associated Plants

White pine, red pine, white oak, black oak, red oak, hemlock, Hill's oak, aspen, paper birch, balsam fir, sugar maple, chokecherry, white cedar, big leaf aster, buffaloberry, thimbleberry, rattlesnake plantain orchid, harebell, wild sarsaparilla, Solomon's seal, and bracken fern.

Management

This species requires openings. In addition, it likely requires some disturbance to maintain the successional character of forests.

General Survey Guidelines

Random meander search covers areas that appear likely to have rare taxa, based on habitat and the judgment of the investigator.

Survey Methods

Page Citation

Michigan Natural Features Inventory. 2007. Rare Species Explorer (Web Application). Available online at http://mnfi.anr.msu.edu/explorer [Accessed Jun 26, 2017]

More Information

See MNFI Species Abstract

References

Survey References

Technical References

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