Slender, sparsely branched, 1-10 dm; lvs consisting of petioles only, to 35 cm, with a scarious stipular margin toward the base, sometimes with axillary bulblets; rays 3-15, 5-20 mm; bracts minute or none; pedicels 3-15, 1-6 mm; bractlets lanceolate, 1 mm; fr ovoid, 1.5-2 mm; 2n=12. Wet riverbanks and highly saturated soils; Potomac Valley of Md.; Va. and W.Va., s. to S.C., Ga., and n. Ala. July-Oct. (P. fluviatile; P. viviparum; Harperella f.; Harperella n.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
