Sagittaria graminea Michx.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Erect and emersed or lax and submersed; rhizome short; lvs bladeless, flat, phyllodial, or with lance-linear to broadly elliptic-ovate blade, very rarely hastate or sagittate, 4–30 × 0.5–10 cm; scape simple or sometimes branched at the base of the infl, 0.3–5 dm; fls in 2–12 whorls, the upper usually staminate on slender, erect pedicels, the lower pistillate on thicker, ascending pedicels; bracts 3–15 mm, connate up to half-length; sep ovate, 3–6 mm, reflexed in fr; pet white or pink, 1–2 cm, often as wide; stamens 12–many; filaments dilated, roughened with minute scales; achenes 1.2–3 mm, winged on the margins and with one or more facial wings, the beak less than 0.75 mm; 2n=22. Swamps, mud, and shallow water; Nf. and s. Lab. to Minn. and S.D., s. to Cuba and Tex. July–Sept. Three vars. with us.