Stem decumbent or floating; lvs decompound; lfls of submersed lvs filiform, of aerial lvs ovate, 1-2 cm, deeply pinnatifid into obtuse segments; fr ovate-oblong, 4-5 mm, tipped by the sep and ascending styles; 2n=22. Aquatic; native of Eurasia, adventive at Washington, D.C., in O., and doubtless elsewhere in our range.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.