1a. Lythrum alatum Pursh var. alatum
[E F W]
Lythrum dacotanum Nieuwland
Stems mostly less than 10 dm, often 1+ stems closely arising from enlarged rootstock. Leaf blades ovate to oblong, base subcordate to rounded. 2n = 20.
Flowering summer. Wet soil, low, open fields, prairies, woodland margins; 50–1500 m; Ont.; Ala., Ark., Colo., Conn., D.C., Fla., Ga., Ill., Ind., Iowa, Kans., Ky., Maine, Md., Mass., Mich., Minn., Miss., Mo., Nebr., N.H., N.J., N.Y., N.Dak., Ohio, Okla., Pa., R.I., S.Dak., Tenn., Vt., Va., W.Va., Wis., Wyo.; introduced in Mexico.
Lythrum cordifolium Nieuwland is a later homonym that pertains here.
