The genus name to Eleocharis comes from the Greek "elos" for marsh and "charis" for grace. With more herbarium work and field study we might find that this little Eleocharis graces many more of the marshes in our state. This and many other Eleocharis species are important wildlife food for wetland birds and other animals. You can often see damselflies and dragonflies perching on the tops of the stems.
There are three existing populations but only one of them contained over 100 plants. One other population was on a river sandbar and may be gone and four other populations were composed of only a few plants. There are about 10 historical records from upstate New York and the Adirondacks which have not been checked.
The short-term trend may be declining as most existing populations were small and in dynamic habitats. Two of largest populations have not been relocated recently. Current survey work is needed to see if this species still exists in New York.
It is unclear if the long-term trend is declining because many historical sites in upstate New York have not been resurveyed specifically for this species.
Specific threats to all of these populations have not been determined but one population was found to be chewed by ducks and others could be threatened by shoreline succession or erosion.
Existing habitat needs to be protected from succession or direct human destruction. Shorelines should be allowed to remain dynamic and open.
Studies are needed to determine habitat preference and how populations respond to the dynamic habitat where they grow. Population augmentation studies could be done to see if existing populations can be enlarged.
More habitat information is needed for this species in New York. It has been collected from artificial ponds, shallow natural ponds in larger swamps, and from marshy area on river islands (New York Natural Heritage Program 2007). Wet, open places, local (Fernald 1970). Marshes and other wet places, sometimes intertidal (Gleason 1952).
Most Eleocharis ovata collections in New York have been from Suffolk County on Long Island, though there have been widely scattered collections from across the state.
Eleocharis ovata is found in most of the midwestern and northeastern US states, in eastern Canada from Newfoundland to Ontario, and is disjunct to Western Canada, Washington, Oregon, and Arizona. It also occurs in Eurasia.
Spikerushes consist of a simple stem (the leaves bladeless and inconspicuous), with the infloresence consisting of a solitary, many-scaled spikelet at the top of the stem. The perianth (sepals and petals), if present, is reduced to (usually 3 or 6) bristles. The base of the style is expanded into a tubercle, and is usually persistent on the fruit (achenes). Eleocharis ovata is an annual species, from 2 to 35 cm high, with ovoid spikelets 2-8 mm high by 2-4 mm wide. The achenes are lenticular, light to dark brown, shining, and 1 mm long. The tubercles are short, higher than wide, flattened, broad-based, and about half as broad as the achenes. The bristles clearly overtop the achenes.
E. engelmannii has tubercles as broad as the achenes. E. obtusa has mostly 3-parted styles and 3 stamens, and wider (.5 to .8 mm) tubercles.
Eleocharis ovata fruits from July to mid-October.
The time of year you would expect to find Ovate Spike Rush fruiting in New York.
Ovate Spike Rush
Eleocharis ovata (Roth) Roemer & J.A. Schultes
Flora of North America Editorial Committee. 2002. Flora of North America, North of Mexico. Volume 23. Magnoliophyta: Commelinidae (in part): Cyperaceae. Oxford University Press, New York. 608 pp.
Crow, Garrett E. and C. Barre Hellquist. 2000. Aquatic and wetland plants of northeastern North America: A revised and enlarged edition or Norman C. Fassett's a manual of aquatic plants. Volume two angiosperms: Monocotyledons. The University of Wisconsin Press. Madison, Wisconsin. 456 pp.
Fernald, M.L. 1950. Gray's manual of botany. 8th edition. D. Van Nostrand, New York. 1632 pp.
Gleason, Henry A. and A. Cronquist. 1991. Manual of Vascular Plants of Northeastern United States and Adjacent Canada. The New York Botanical Garden, Bronx, New York. 910 pp.
Haines, Arthur and Thomas F. Vining. 1998. Flora of Maine. A Manual for Identification of Native and Naturalized Vascular Plants of Maine.
Haines, Arthur. 2003. Eleocharis aestuum (Cyperaceae) in New York. NY Flora Association Newsletter. Vol 14(1): 4-6. March 2003.
Holmgren, Noel. 1998. The Illustrated Companion to Gleason and Cronquist's Manual. Illustrations of the Vascular Plants of Northeastern United States and Adjacent Canada. The New York Botanical Garden, Bronx, New York.
Larson, B.M.H. and P.M. Catling. 1996. The separation of Eleocharis obtusa and Eleocharis ovata (Cyperaceae) in eastern Canada. Canad. J. Bot. 74: 238-242.
New York Natural Heritage Program. 2010. Biotics database. New York Natural Heritage Program. New York State Department of Environmental Conservation. Albany, NY.
New York Natural Heritage Program. 2021. New York Natural Heritage Program Databases. Albany, NY.
Voss, E.G. 1972. Michigan Flora, Part I. Gymnosperms and Monocots. Cranbrook Institute of Science Bulletin 55 and the University of Michigan Herbarium. Ann Arbor. 488 pp.
Weldy, T. and D. Werier. 2010. New York flora atlas. [S.M. Landry, K.N. Campbell, and L.D. Mabe (original application development), Florida Center for Community Design and Research http://www.fccdr.usf.edu/. University of South Florida http://www.usf.edu/]. New York Flora Association http://newyork.plantatlas.usf.edu/, Albany, New York
Weldy, Troy W. and David Werier. 2005. New York Flora Atlas. [S.M. Landry, K.N. Campbell, and L.D. Mabe (original application development), Florida Center for Community Design and Research. University of South Florida]. New York Flora Association, Albany, NY. Available on the web at (http://newyork.plantatlas.usf.edu/).
Information for this guide was last updated on: January 18, 2008
Please cite this page as:
New York Natural Heritage Program. 2021. Online Conservation Guide for Eleocharis ovata. Available from: https://guides.nynhp.org/ovate-spike-rush/. Accessed October 25, 2021.