Northern water-plantain, alisma commun

Alisma plantago-aquatica Linnaeus var. americanum Schultes & Schultes f.

Herbs, to 1 m. Leaves emersed, petiolate; blade linear-lanceolate to broadly elliptic or oval, to 35 ´ 3--12 cm. Inflorescences to 1 m. Flowers chasmogamous; sepals 3--6 mm; petals white, 3.5--6 mm, margins ± erose, apex obtuse; anthers ovoid, 0.6--1 mm; style ± curved, 0.4--0.6 mm, equal to ovary length. Fruiting heads 4.1--7 mm diam; achenes ovoid, 2.1--3 mm, abaxial keel broadly rounded with 1 median abaxial groove, beak erect or nearly erect. 2n = 28.

Flowering spring--fall. Shallow muddy ponds, stream margins, marshes, and ditches; 0--2000 m; Alta., B.C., Man., N.B., Nfld. and Labr., N.W.T., N.S., Ont., P.E.I., Que., Sask.; Alaska, Ariz., Calif., Colo., Conn., Idaho, Ill., Ind., Iowa, Kans., Maine, Mass., Mich., Minn., Mont., Nebr., Nev., N.H., N.Mex., N.Y., N.Dak., Ohio, Okla., Oreg., Pa., R.I., S.Dak., Utah, Vt., Wash., Wis., Wyo.; n Mexico.

I have seen no specimens from West Virginia, but although the species is to be expected there.