Photo by John V. Freudenstein
Very small forb of rock crevices on Isle Royale; basal leaves tufted and obovate (1-2 cm long) with lime-encrusted pores on the toothed margins; five-petaled flowers white, dotted with red or purple.
Status and Rank
- State Status: T - Threatened (legally protected)
- State Rank: S1 - Critically imperiled
- Global Rank: G5 - Secure
|County Name||Number of Occurrences||Year Last Observed|
Updated 05/08/2013. 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.
Encrusted saxifrage is a boreal plant found on exposed or sheltered rocky shoreline along Lake Superior. In Michigan, it is currently known only from Isle Royale and surrounding islands.
Natural Community Types
Paper birch, black crowberry, dwarf raspberry, alpine bilberry, serviceberry, fescue, trisetum, harebell, fir clubmoss, sand cress, mosses, lichens, ticklegrass, yarrow, bearberry, marsh bellflower, pale Indian paintbrush, hair grass, spike-rush, butterwort, ninebark, silverweed, dwarf Canadian primrose, and wild rose.
This species 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. May also be vulnerable to excessive foot traffic.
General Survey Guidelines
Random meander search covers areas that appear likely to have rare taxa, based on habitat and the judgement of the investigator.
- Meander search
Survey Period: From first week of July to fourth week of July
More InformationSee MNFI Species Abstract
- Elzinga, C.L., D.W. Salzer, and J.W. Willoughby. 1998. Measuring and Monitoring Plant Populations. The Nature Conservancy and Bureau of Land Management, Denver. BLM Technical Reference 1730-1. 477pp.
- Goff, G.F., G.A. Dawson, and J.J. Rochow. 1982. Site examination for Threatened and Endangered plant species. Environmental Management 6(4): 307-316
- Nelson, J.R. 1984. Rare Plant Field Survey Guidelines. In: J.P. Smith and R. York. Inventory of rare and endangered vascular plants of California. 3rd Ed. California Native Plant Society, Berkeley. 174pp.
- Nelson, J.R. 1986. Rare Plant Surveys: Techniques For Impact Assessment. Natural Areas Journal 5(3):18-30.
- Nelson, J.R. 1987. Rare Plant Surveys: Techniques for Impact Assessment. In: Conservation and management of rare and endangered plants. Ed. T.S. Elias. California Native Plant Society, Sacramento. 8pp.
- Coffin, B. and L. Pfannmuller, eds. 1988. Minnesota's Endangered Flora and Fauna. University of Minnesota Press, Minneapolis. 473pp.
- Gleason, H. A., and A. Cronquist. 1991. Manual of Vascular Plants of Northeastern United States and Adjacent Canada. Second edition. The New York Botanical Garden, Bronx. 910pp.
- Gray, A. 1950. Gray's Manual of Botany; eighth ed. Van Nostrand Reinghold, New York. 1632pp.
- Holmgren, N.H. 1998. Illustrated Companion to Gleason and Cronquist's Manual. Illustrations of the vascular plants of Northeastern United States and adjacent Canada. New York Botanical Garden, Bronx. 937pp.
- Scoggan, H.J. 1978. The Flora of Canada. National Museum of Natural Science Publications Botany 4: 1711pp.
- Voss, E. G. 1985. Michigan Flora. Part II. Dicots (Saururaceae-Cornaceae). Bulletin of the Cranbrook Institute of Science and University of Michigan Herbarium. 724pp.