Eleocharis acicularis (L.) Roem. & Schult.
Common Name: SPIKE-RUSH
Coefficient of Conservatism: 7
Coefficient of Wetness: -5
Wetness Index: OBL
Physiognomy: Nt P-Sedge

Wet sandy or mucky shores and hollows, mud flats, river banks.

Small plants, with hair-like culms, often about 5 cm tall (sometimes 10 cm or even more if submersed—see couplets 26–28 of Key A, to aquatic plants with all leaves floating or submersed); the tufts (connected by slender rhizomes) may form dense carpets, both on wet shores and submersed. Two other common small species (though usually with slightly thicker culms) are sometimes confused with this one, at least when mature achenes are not present: E. intermedia and E. flavescens. In E. intermedia the anthers are less than 0.5 mm long; in the other two species, 0.5–1 mm. The basal scales of the spikelets in E. acicularis are fertile; in E. intermedia and E. flavescens, they are sterile. Eleocharis flavescens and to some extent E. acicularis both have the sheaths thin, whitish, and loose at the summit. Eleocharis quinqueflora when very young may be readily distinguished by its much larger anthers (ca. 1.5–2.5 mm) and rather prominent blunt often slightly swollen tips on the vegetative culms.

Locations

Alpena County
Baraga County
Barry County
Bay County
Berrien County
Calhoun County
Cass County
Charlevoix County
    Only on Beaver Island
Cheboygan County
Chippewa County
    Including Drummond Island
Clinton County
Delta County
Emmet County
Genesee County
Gogebic County
Gratiot County
Hillsdale County
Houghton County
Huron County
Ingham County
Ionia County
Iron County
Isabella County
Jackson County
Kalamazoo County
Kalkaska County
Kent County
Keweenaw County
    Including Isle Royale
Lake County
Lapeer County
Lenawee County
Livingston County
Luce County
Mackinac County
Macomb County
Manistee County
Marquette County
Mecosta County
Menominee County
Midland County
Monroe County
Montmorency County
Muskegon County
Newaygo County
Oakland County
Ontonagon County
Ottawa County
Presque Isle County
Roscommon County
Schoolcraft County
St. Clair County
St. Joseph County
Tuscola County
Van Buren County
Washtenaw County
Wayne County
Wexford County

Citation:

MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. December 18, 2017. http://www.michiganflora.net/species.aspx?id=1100.