Small aquatic or marsh herbs, with a 2-lipped calyx and a personate corolla with a spur or sac underneath. Stamens 2. Ovary as in Primulaceae. Chiefly represented by the two following genera:1. Utricularia L. Bladderwort.
1. U.vulga'ris, L. (Greater Bladderwort.) Immersed leaves crowded, finely dissected into capillary divisions, furnished with small air-bladders. Flowers yellow, several in a raceme on a naked scape. Corolla closed; the spur conical and shorter than the lower lip. - Ponds and slow waters.
2. U. interme'dia, Hayne. Immersed leaves 4 or 5 times forked, the divisions linear-awl-shaped, minutely bristle-toothed on the margin, not bladder-bearing, the bladders being on leafless branches. Stem 3-6 inches long. Scape very slender, 3-6 inches long, bearing few yellow flowers. Upper lip of the corolla much longer than the palate; the spur closely pressed to the broad lower lip. - Shallow waters.
3. U. cormuta, Michx., with an awl-shaped spur turned downward and outward, and the lower lip of the corolla helmet-shaped, is not uncommon in the northern parts of Ontario. Flowers yellow. Leaves awl-shaped.
4. U. clandesti'na, Nutt. Stems and scapes slender. Leaves hair-like, bearing small bladders. Corolla yellow; lower lip 3-lobed, longer than the thick, blunt spur. Submerged stems bearing cleistogamous flowers. - Ponds, Atl. Prov.
5. U. gib'ba, L. Scape only 1-3 inches high, 1-2-flowered, with very slender short branches at the base, bearing capillary root-like leaves and scattered bladders. Corolla yellow, the lower lip with sides reflexed. Spur very thick and blunt, conical, gibbous. - Shallow water, central and S. W.
P. vulga'ris, L. A small and stemless perennial growing on damp rocks. Scapes 1-flowered. Leaves entire, ovate or elliptical, soft-fleshy, clustered at the root. Upper lip of the calyx 3-cleft, the lower 2-cleft. Corolla violet, the lips very unequal, the palate open, and hairy or spotted. - Shore of Lake Huron.