Saxifraga tricuspidata
Prickly saxifrage
Image of Saxifraga tricuspidata

Photo by Marilyn Keigley 

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Key Characteristics

Very small forb of rock crevices on Isle Royale; basal leaves tufted and oblong (1-2 cm long) with 3 spine-tipped teeth at their apex (otherwise smooth on the margin); five-petaled flowers white, dotted with red or purple.

Status and Rank

  • State Status: T
  • State Rank: S2
  • Global Rank: G5

Occurrences

County NameNumber of OccurrencesYear Last Observed
Keweenaw101994
Distribution map for Saxifraga tricuspidata

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

Prickly saxifrage is found on exposed, sunny bedrock shores of Lake Superior, particularly around Isle Royale.

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

Creeping juniper, bearberry, harebell, ticklegrass, yarrow, marsh bellflower, pale Indian paintbrush, hair grass, spike-rush, butterwort, ninebark, silverweed, dwarf Canadian primrose, and wild rose.

Management

Primarily requires protection of the Lake Superior 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.

General Survey Guidelines

Random meander search covers areas that appear likely to have rare taxa, based on habitat and the judgement 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 Aug 18, 2017]

More Information

See MNFI Species Abstract

References

Survey References

Technical References

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