Rare Species Guide

  Synonyms

Eleocharis pauciflora, Eleocharis pauciflora var. fernaldii

  Basis for Listing

In Minnesota, Eleocharis quinqueflora occurs in a class of peatland that is identified by ecologists as a "non-forested fen". The highly specialized plants that occur in fens have attracted the attention of botanists for a long time, especially in the last few decades. As a result, there is a considerable amount of floristic data to draw upon when trying to determine which fen species are in need of special management consideration. It is clear that E. quinqueflora falls within that category. It is certainly rare, being absent from the great majority of fens, and it occurs in small, transient populations that are sensitive to a variety of ecosystem perturbations. Eleocharis quinqueflora was listed as a special concern species in Minnesota in 1984.

  Description

Eleocharis quinqueflora is a perennial graminoid with creeping rhizomes. Stems stand erect and are arranged in small tufts. They are 5-15 cm (2.0-5.9 in.) tall and 0.2-0.5 mm (0.008-0.020 in.) wide, and at the tip of each stem is a 3-8 mm (0.12-0.31 in.) long spikelet with 3-10 small flowers. The seeds (achenes) are 3-sided, obpyriform in shape, lack longitudinal ridges, and are 1.6-2.3 mm (0.06-0.09 in.) long and 0.7-1.3 mm (0.03-0.05 in.) wide. At the tip of the seed is a tubercle or protuberance 0.3-0.4 mm (0.01-0.02 in.) tall and 0.2-0.3 mm (0.008-0.012 in.) wide. Reproductive bulbs are often found among the stem bases and on the rhizomes. Among all the spike-rush species in Minnesota, E. quinqueflora is notable for being short in stature and having relatively few flowers, usually fewer than 10.

  Habitat

Eleocharis quinqueflora occurs primarily in sparsely vegetated wet habitats found in graminoid fens, shorelines of ponds and small lakes, and occasionally in wet prairie openings. Over two-thirds of the occurrences are in the western part of the state in the Prairie Parkland and Tallgrass Aspen Parklands provinces, primarily in mineral-rich calcareous fens and prairie rich fens (Minnesota Department of Natural Resources 2005) where marl or salts are concentrated at the surface. It has also been found in wet openings or well-trampled animal trails in northern wet prairie. A few occurrences of this species are also located in calcareous fens in the northern portion of the Eastern Broadleaf Forest Province.

Within the northeastern part (Northern Superior Uplands) of the Laurentian Mixed Forest Province, E. quinqueflora is found on floating peat mats bordering small lakes and ponds that are primarily northern rich fen and possibly northern shrub shore fen, although some sites may be approaching poor fens conditions. However, in the north central portion of the state (Northern Minnesota Drift and Lake Plains), this species has been found only in wet sand and occasionally muddy shores along the margins of small lakes that appear to have fluctuating water levels.

  Biology / Life History

Reproductive bulbs can usually be found at the base of the stems and at the tips of short rhizomes. If detached, these bulbs can be carried some distance on water currents and possibly by small animals. If one such bulb is deposited on a suitable substrate, it can develop into a new plant. Eleocharis quinqueflora can also reproduce by seeds, which are usually produced every year.

The best time to search for E. quinqueflora is during August and the first half of September, when mature achenes are most likely to be present.

  Conservation / Management

The primary habitat of E. quinqueflora in Minnesota is non-forested fens. Fens of this type are typically densely vegetated and quite stable in terms of species composition. However, there are normally occasional, small openings or gaps in the vegetation, which might expose bare peat. These openings might occur along the edge of a small pond or pool, along a frequently-used game trail or beaver run, or in a groundwater discharge zone. There is some evidence that E. quinqueflora requires these openings for reproduction or establishment. In a full-functioning habitat where water levels are responding to seasonal weather patterns and fluctuations in water levels and wildlife are present in normal abundance and diversity, standard ecosystem processes should provide adequate openings for E. quinqueflora.

  Conservation Efforts in Minnesota

Eleocharis quinqueflora occurs at a number of sites that are in public ownership. Most of the publicly-owned sites are managed for human recreation (primarily hunting), timber production, or conservation. However, no known conservation efforts have been undertaken to specifically manage for the species within these areas.

  References and Additional Information

Minnesota Department of Natural Resources. 2003. Field guide to the native plant communities of Minnesota: the Laurentian mixed forest province. Ecological Land Classification Program, Minnesota County Biological Survey, and Natural Heritage and Nongame Research Program. Minnesota Department of Natural Resources, St. Paul, Minnesota. 352 pp.

Smith, S. G., J. J. Bruhl, M. S. Gonzalez-Elizondo, and F. J. Menapace. 2002. Eleocharis. Pages 60-120 in Flora of North America Editorial Committee, editors. Flora of North America north of Mexico. Volume 23. Oxford University Press, New York, New York.

Smith, W. R. 2018. Sedges and rushes of Minnesota: the complete guide to species identification. University of Minnesota Press, Minneapolis. 696 pp.