SPARGANIUM EMERSUM Rehmann
HABIT: Emersed perennial herb to 6 dm.; flowering
June-August; fruiting August, September.
SIMILAR SPECIES: Sparganium chlorocarpum is the only member
of this genus in Ohio in which at least the lowest pistillate head is
supra-axillary, due to fusion of the peduncle with the stem. However,
examination of technical fruit characters is needed for positive
TOTAL RANGE: Nfld. and Que. to MN and ND, s. to s. NY, WV,
IN, and IA.
STATE RANGE: The species was rediscovered for Ohio
in Portage County in 1998. There is a 1969 record from Williams County.
Pre-1960 collections exist from Champaign, Franklin, and Pike counties.
STATE STATUS: 1980-1989: Endangered, 1990-1997: Presumed
Extirpated, 1998 to present: Endangered.
HABITAT: A variety of wet, open to semi-open situations:
muddy or peaty shores, swamps, marshes, or shallow water.
HAZARDS: Drainage or other alteration of the wetland
habitat; overshading by taller species as a result of succession.
RECOVERY POTENTIAL: Unknown, but possibly good in northwest
Ohio due to its frequency in adjacent states (see Comments).
INVENTORY GUIDELINES: Mature fruiting material is needed for
COMMENTS: S. chlorocarpum is fairly common in
Michigan and northern Indiana, and could thus quite possibly be found in other
counties of northwest Ohio. It may have been overlooked due to the difficulty
of collecting it in its wetland habitat. The species should also be sought in northeast Ohio.
Beal, E.O. 1960. Sparganium (Sparganiaceae) in the
southeastern United States. Brittonia 12: 176-181.
Crow, G.E. and C.B. Hellquist. 1981. Aquatic vascular plants
of New England: Part 2. Typhaceae and Sparganiaceae. New Hampshire Agr. Exp.
Sta. Bull. 517. 21 p.
Flora of North America Editorial Committee, eds. 1993+.
Flora of North America North of Mexico. 4+ vols. New York and Oxford. (The
Sparganiaceae is treated in Volume 22.)
Ohio Department of Natural Resources
Division of Natural Areas and Preserves
Created: 11/1983 James F. Burns