Wolffia gladiata Hegelmaier, Lemnac., 133. 1868; W. gladiata var. floridana Donnell Smith; Wolffiella floridana (Donnell Smith) C. H. Thompson;

Fronds 1 or 2--20 or more, coherent in starlike groups, narrowly sabre-shaped, 3--9 mm, (4--)6--15(--20) times as long as wide, pointed at tip; tract of elongated cells running along edge of lower wall of pouch; area of air spaces much longer than wide, spreading throughout most of frond; angle of pouch 25°--50°; flowering fronds much wider at base than vegetative ones. Fruits 0.3--0.4 mm. 2n = 40, 42.

Flowering (very rare) spring and fall. Mesotrophic, quiet waters in warm-temperate regions with relatively mild winters; 0--400 m; Ala., Ark., Del., D.C., Fla., Ga., Ill., Ind., Ky., La., Md., Mass., Miss., Mo., N.J., N.C., Ohio, Okla., Pa., S.C., Tenn., Tex., Va., Wash.; Mexico (Federal District).

The type collection of Wolffiella gladiata, from Mexico City, is taxonomically identical with plants from Florida called W. gladiata var. floridana by J. D. Smith. Some authors included narrow specimens of W. oblonga in W. gladiata, causing confusion.

I know of no specimens of Wolffiella gladiata from Rhode Island.