Carex seorsa

Key Characteristics

Densely clumped sedge of deciduous swamps; leaves 2-4 mm; culms lax and spreading; perigynia flattened and strongly reflexed with short, smooth beaks.

Status and Rank

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


County NameNumber of OccurrencesYear Last Observed
Van Buren32006
Distribution map for Carex seorsa

Updated 5/15/2018. 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.


Found on hummocks in hardwood or hardwood-conifer swamps, margins of bogs, and buttonbush depressions. Often found at edges of woodland pools or at the swamp-upland border.

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

Red maple, Michigan holly, buttonbush, bracken fern, Canada mayflower, cinnamon fern, and sedges (Carex canescens, C. trisperma).


Maintain hydrological regime and forest canopy. This species may be impacted by excessive timber harvesting and other artificial disturbances.

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 [Accessed Sep 23, 2018]


Survey References

Technical References

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