Stuckenia filiformis

HABIT: Submersed aquatic, creeping extensively by filiform stolons, terminated by slender white tubers; flowering July-September; fruiting August-October.

SIMILAR SPECIES: Sterile specimens of Ruppia may be mistaken for P. filiformis, but differ in that the summit of the open sheathing leaf bases of Ruppia are at most slightly auriculate as opposed to having definite free stipules.

TOTAL RANGE: Circumboreal; in America s. to ME, PA, OH, MI, MN, and AZ.

STATE RANGE: There is a post-1960 record from Ottawa County. Pre-1960 occurrences are recorded for Auglaize, Mercer, and Miami counties.

STATE STATUS: 1980-1991: Endangered, 1992 to present: Presumed Extirpated.

HABITAT: Lakes and rivers, at depths up to at least a meter, but apparently fruiting best in shallow water over a sandy bottom.

HAZARDS: Unknown, but perhaps turbidity or mechanical disturbance.

RECOVERY POTENTIAL: Probably poor. However, improved water quality may lead to establishment of additional populations. The species may likely never be well established in Ohio, owing to the warm waters of the state.

INVENTORY GUIDELINES: Every effort should be made to obtain fruiting specimens; however, in the absence of fruiting material, sterile specimens should be collected.

COMMENTS: While somewhat unlikely, this species, like other pondweeds, may unexpectedly become established in suitable waters. It should be sought in northern and western Ohio.

This species is not reported in Braun (1967). However, good keys for the northern pondweeds, including P. filiformis, can be found in Voss (1972), and Hellquist and Crow (1980).

SELECTED REFERENCES:

Braun, E.L. 1967. The Monocotyledoneae of Ohio : Cat-tails to orchids. The Ohio State University Press, Columbus, OH. 464 p.

Fernald, M.L. 1932. The linear-leaved North American species of Potamogeton, section Axillares. Mem. Am. Acad. 17: 1-183.

Hellquist, C.B. 1977. Observations on some uncommon vascular aquatic plants in New England. Rhodora 79: 445-452.

Hellquist, C.B. and G.E. Crow. 1980. Aquatic vascular plants of New England: Part l. Zosteraceae, Potamogetonaceae, Zannichelliaceae, Najadaceae. New Hampshire Agr. Exp. Sta. Bull. 515. 68 p.

Ogden, E.C. 1974. Potamogeton in New York. New York St. Museum Bull. No. 423, Albany, NY. 20 p.

Voss, E.G. 1972. Michigan flora, Part I. Gymnosperms and monocots. Cranbrook Inst. of Sci. Bull. 55, Bloomfield Hills, MI. 488 p.

Ohio Department of Natural Resources

Division of Natural Areas and Preserves

Created: 11/1983 John Marshall