L. trisulca: aquatic; fronds floating, thin, oblong, minutely-toothed at the top, and ending in a little stalk at the base, with young ones growing at right angles from opposite sides, each with a single root beneath. - Ponds and still waters. Fl. June, but rarely.

L. minor: aquatic; fronds floating, small, broadly ovate or orbicular, thickish, cohering three or four together, with one root under each, not stalked. - Ponds and still waters. Fl. June, July, not unfrequent.

L. gibba: aquatic; fronds floating, obovate, larger and much thicker than the last, flat above, spongy and almost hemispherical beneath, with a single root to each. - Ponds and still waters, rather rare. Fl. June, July, rarely.

L. polyrrhiza: aquatic; fronds larger, floating, broadly ovate or orbicular, thickish, each with a cluster of roots beneath. - Still waters. Fl. not observed.