Eleocharis equisetoides
Horsetail spike rush
Image of Eleocharis equisetoides

Photo by Ryan P. O'Connor 

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Key Characteristics

Large clone-forming aquatic emergent spike-rush (150 cm) of softwater lakes; culms hollow, yellowish-green and very thick (5-10 mm), resembling a horsetail (Equisetum) with superficial joints and cross-partitions.

Status and Rank

  • State Status: SC
  • State Rank: S3
  • Global Rank: G4

Occurrences

County NameNumber of OccurrencesYear Last Observed
Barry32010
Cass21915
Hillsdale11989
Jackson42010
Kalamazoo11936
Livingston32011
Montcalm11941
St. Joseph11954
Van Buren21915
Washtenaw62014
Distribution map for Eleocharis equisetoides

Updated 7/21/2017. 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

Found in shallow water in emergent marshes, lakeshore edges and ponds, particularly where waters or substrates are slightly acidic.

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

Water-plantain, sedges, spike-rush, northern manna grass, cut grass, smartweed, arrowhead, bur-reed, cat tails, wild rice, water-milfoil, watercress, great duckweed, three square bulrush, water-lily, spatterdock, and pondweed.

Management

Protect habitat; maintain wetland hydrology and natural cycle of fluctuations in emergent marsh. Agricultural run-off has negative impacts. Protect habitat from development.

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 Nov 22, 2017]

References

Survey References

Technical References

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