Monographs Details: Nuphar sagittifolia (Walter) Pursh
Authority: Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Description:Species Description - Lvs both floating and submerged, oblong-lanceolate, 15–40 × 5–10 cm, the basal sinus only 2–5 cm; fls 2.5–3 cm thick; anthers 3–4 mm; stigmatic disk 8–15 mm wide at anthesis, 10–14-rayed. Tidal reaches of streams; Va. to S.C. Summer. A hybrid with N. advena has been called N. ×interfluitans Fernald.