Plants and Animals

Rubus acaulis Dwarf raspberry

species photo
Susan R. Crispin

Key Characteristics

Small tufted forb of minerotrophic peatlands in the Upper Peninsula; stems upright and spineless, bearing trifoliate leaves, the terminal one broadly ovate and short-stalked, the lateral ones sessile, often with a small thumb-like lobe on the side; 5- parted flowers are deep pink, borne on long glandless stalks.

Status and Rank

US Status: No Status/Not Listed
State Status: T - Threatened (legally protected)
Global Rank: G5T5
State Rank: S1 - Critically imperiled


CountyNumber of OccurrencesYear Last Observed
Chippewa 4 2015
Keweenaw 1 2020
Luce 1 2011
Marquette 1 2010
Schoolcraft 3 2015

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.


A boreal species found in open to partially forested poor to rich fens, often on hummocks at the margins of large peatland complexes.

Natural Community Types

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

Trees: Larix laricina (tamarack), Picea mariana (black spruce), Pinus strobus (white pine), Thuja occidentalis (northern white-cedar).

Shrubs: Alnus incana (tag alder), Andromeda glaucophylla (bog-rosemary), Aronia prunifolia (chokeberry), Betula pumila (bog birch), Chamaedaphne calyculata (leatherleaf), Dasiphora fruticosa (shrubby cinquefoil), Lonicera villosa (mountain fly honeysuckle), Myrica gale (sweet gale), Rhamnus alnifolia (alder-leaved buckthorn), Rhododendron groenlandicum (Labrador-tea), Vaccinium oxycoccos (small cranberry).

Herbs: Anemone quinquefolia (wood anemone), Calamagrostis canadensis (blue-joint), Carex exilis, C. lasiocarpa, C. livida, Cladium mariscoides (twig-rush), Comarum palustre (marsh cinquefoil), Coptis trifolia (goldthread), Doellingeria umbellata (flat-topped white aster), Drosera rotundifolia (round-leaved sundew), Equisetum fluviatile (water horsetail), Iris versicolor (northern blue flag), Linnaea borealis (twinflower), Maianthemum trifolium (false mayflower), Muhlenbergia glomerata (marsh wild-timothy), Oclemena nemoralis (bog aster), Osmunda regalis (royal fern), Pogonia ophioglossoides (rose pogonia), Pyrola americana (round-leaved pyrola), Rhynchospora alba (beak-rush), Sarracenia purpurea (pitcher-plant), Solidago rugosa (rough-leaved goldenrod), S. uliginosa (bog goldenrod), Trichophorum alpinum (Alpine bulrush), T. cespitosum (tufted bulrush).

Management Recommendations

The species primarily requires perpetuation of hydrological regime and protection of habitat. It is likely vulnerable to logging activities that impact peatlands.

Survey Methods

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

  • Meander search

    • Survey Period: From third week of May to second week of September


Survey References

  • 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.

Technical References

  • 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.