Cystopteris tennesseensis
Tennessee bladder fern

Key Characteristics

Low arching fern (30-50 cm) of calcareous cliffs and crevices; blades twice-divided, narrowly deltate, widest near the base; rachis and pinnae axis with occasional gland-tipped hairs.

Status and Rank

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

Occurrences

County NameNumber of OccurrencesYear Last Observed
Chippewa11950
Distribution map for Cystopteris tennesseensis

Updated 1/31/2017. 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

This species is known only from a couple of sites on shaded calcareous cliffs and crevices in the Upper Peninsula. Status surveys are needed for this newly listed species.

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

Very little data exists on this rare fern; the one collection in which associates were mentioned it was noted to occur beneath paper birch and maple in a cut-over coniferous woods (likely of balam fir, white pine, or white spruce).

Management

Generally requires shade and moist, moss-covered limestone or dolomite boulders, cliffs, and crevices. The 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.

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 Jun 27, 2017]

References

Survey References

Technical References

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