Plants and Animals

Asplenium viride Green spleenwort

species photo
Eric J. Epstein

Key Characteristics

Small fern (5-15 cm) of calcareous cliffs and crevices; fronds pinnate with small (1 cm), opposite, oval pinnae; rachis green except at base.

Status and Rank

US Status:
State Status: SC - Special Concern (rare or uncertain; not legally protected)
Global Rank: G4 - Apparently secure
State Rank: S3 - Vulnerable

Occurrences

CountyNumber of OccurrencesYear Last Observed
Chippewa41993
Keweenaw12014
Leelanau21986
Mackinac182014
Marquette11980
Schoolcraft21978

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

Found in northern hardwoods as well as on limestone cliffs, dolomite boulders and outcrops, mainly in the Niagaran Escarpment region in the eastern Upper Peninsula. Less commonly occurs on dolomite boulders within conifer-dominated uplands and swamp forests. It is frequently found with walking fern and often with Hart's tongue fern.

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

Walking fern, polypody, maidenhair spleenwort, northern holly fern, Hart's tongue fern, Braun's Christmas fern.

Management Recommendations

Generally requires shade and moist, moss-covered limestone or dolomite boulders. Species may be sensitive to drying and scorching from overexposure to sunlight. Maintain overstory and minimize development and fragmentation. When possible, leave large tracts of unharvested forests and allow natural processes (growth, senescence, wind throw, fire, disease, insect infestation, etc) to operate unhindered. If forest is being managed for timber, minimize fragmentation, leave long periods of recuperation between harvests (50-70 yrs.), preserve as much area as possible in a forested matrix, and maintain a range of canopy closure comparable to pre-harvest closure.

Survey Methods

Random meander search covers areas that appear likely to have rare taxa, based on habitat and the judgement of the investigator. A systematic survey follows transects as a guide to provide the greatest coverage possible of the area. Greatest coverage occurs with parallel transects spaced equidistant over the area.

  • Meander search

    • Survey Period: From first week of June to fourth week of September

      Survey Method Comment:
      Search limestone/dolomite boulders and other outcrops
  • Systematic survey

    • Survey Period: From first week of June to fourth week of September

      Survey Method Comment:
      Search limestone/dolomite boulders and other outcrops
  • References

    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

    • Flora of North America Editorial Committee. 1993. Flora of North America, North of Mexico. Volume 2: Pteridophytes and Gymnosperms. Oxford University Press, New York. 475pp.
    • 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.
    • Lellinger, D.B. 1985. A field manual of ferns and fern allies of the United States and Canada.. Smithsonian Institute Press, Washington D.C. 389pp.
    • Mickel, J.T. 1979. How to know the ferns and fern allies. The Pictured Key Nature Series. William C. Brown Company, Dubuque. 229pp.