Draba incana
Twisted whitlow grass
Image of Draba incana

Photo by Susan R. Crispin 

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Key Characteristics

Small forb (10-40 cm) of rocky shores; basal rosette of small leaves; stem leaves numerous (<20); flowers white with four petals, flower stalk densely hairy; fruits elongated, flattened.

Status and Rank

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

Occurrences

County NameNumber of OccurrencesYear Last Observed
Keweenaw21995
Distribution map for Draba incana

Updated 7/21/2017. 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

Known from rock crevices on small outcrop islands in Lake Superior; inhabits steep northwest facing rock faces with sparse vegetation.

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

Ticklegrass, yarrow, bearberry, marsh bellflower, pale Indian paintbrush, hair grass, spike-rush, butterwort, ninebark, silverweed, dwarf Canadian primrose, wild rose, rough cinquefoil, harebell, and bluejoint grass.

Management

Little known of the biology and ecology of this species, although it likely benefits from disturbance that creates and maintains openings and colonization sites. It primarily requires protection of the shoreline habitat and perpetuation of natural disturbance (winter ice, storms, wind) and hydrological regimes. This community occupies a stressed, potentially unstable environment; many of the species found in this community do not tolerate later stages of succession and require management that prevents woody plant encroachment. Protect from development.

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 Dec 18, 2017]

References

Survey References

Technical References

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