FAMILY: Potamogetonaceae (Zosteraceae, Najadaceae)
HABIT: Submersed aquatic, bushy-branched, and bearing only
submersed leaves, or more elongate and with some branches more prolonged and terminated
by dilated floating leaves; spikes dimorphic or trimorphic; flowering
July-November; fruiting August-November.
SIMILAR SPECIES: The submersed leaves are often curved,
giving the whole bushy plant the aspect of a broad-leaved Najas.
Additionally, P. spirillus has often been confused with P.
diversifolius, partly because of similar appearance, partly because of
confusion of nomenclature; both species having been included in P. dimorphus.
TOTAL RANGE: Nfld. to e. Man., s. to N.S., s. N.E.,
DE, VA, WV, OH, WI, IA, and SD.
STATE RANGE: Post-1950 records are known from Ashtabula,
Jefferson, Lorain, Mahoning, Meigs, Portage, Preble, and Trumbull counties.
STATE STATUS: 1980-1983: Threatened, 1884-1987: Potentially
Threatened, 1988-1995: Threatened, 1996-1999: Endangered, 2000 to present:
HABITAT: Quiet shallow waters of lakes, ponds, wet swales,
and rarely quiet river borders.
HAZARDS: Unknown, but perhaps mechanical disturbance.
RECOVERY POTENTIAL: Probably good, owing to the species'
scattered occurrence in eastern Ohio and its tolerance of warmer waters.
INVENTORY GUIDELINES: Every effort should be made to obtain
fruiting specimens; however, in the absence of fertile material, sterile
specimens should be collected.
COMMENTS: This species may be more common in eastern Ohio
than records indicate, and should be sought in suitable habitats throughout the
Fernald, M.L. 1932. The linear-leaved North American species
of Potamogeton, section Axillares. Mem. Am. Acad. 17: 1-183.
Ogden, E.C. 1974. Potamogeton in New York. New York
St. Museum Bull. No. 423. Albany, NY. 20 p.
Reznicek, A.A., and R.S.W. Bobbette. 1976. The taxonomy of Potamogeton
subsection Hybridi in North America. Rhodora 78: 650-673.
Ohio Department of Natural Resources
Division of Natural Areas and Preserves
Created: 1/1983 John Marshall
Database Code: SPGC.B17