5 U. longirostris Ell. Lvs. submersed, dichotomously divided, segm. setaceous, bearing the vescicles; scapes 1 to 2-flowered; upper lip slightly 3-lobed, lower entire; spur linear-subulate, ascending, emarginate at apex, longer than the lower lip.-Stagnant pools, S. Car. to Fla. Scape 3 to 5' high. Fls. yellow, middle size. Jn.
6 U. biflora Lam. Irregularly whorled, capillaceously divided, root-like, bladder-bearing; scape slender, 2 to 3-flowered, pedicels many times longer than the bract or calyx; spur straight, oblong, acute, appressed to the corolla, and of equal length; fr. erect.-Ditches, S. Car. and Ga. Scape 3 to 4' high, pedicels 3 to 4". May, Jn.
7 U. clandestina Nutt Lvs. all submersed, capillaeeous, multifid, bladder-bearing ; fls. 2 or 3 on the slender scape, also solitary on slender, axillary pedicels among the lvs. on the stem, the latter apetalous, fertile; spur very obtuse, shorter than the 3-lobed lower lip.-Ponds, Mass. (Robbins) to N. J. Sts. almost capillary, 6' to 2f long, with many bladders. Scape 3 to 4' high (seldom seen), with corollas expanding about 3 '. Cauline pedicels 6 to 7" long, the cor. tubular, never opening. Jl
8 U. gibba L. (and Le Conte). Minute, floating, with hair-like lvs. and few utricles; scape 1 to 2-flowered, naked; segm. of the yellow cor. roundish, upper lip emarginate, lower subtrilobate, middle lobe crenate, subrevolute ; spur gibbous (that is), very short and obtuse.- In pools, R. I (Olney), Mass., N. Y. to
Car. Submersed stems dichotomous, short and filiform. Scapes 2 to 3' high, often with but 1 small, yellow flower The lvs. appear rather like fine radicles. Jl.
9 U. tripartita Ell. Lvs. fibrillous-multifid, bearing the bladders; scape 1 to 3-flowered; lower lip of the calyx bifid or 2-parled; cor. lips entire, the lower twice as long as the obtuse spur.- Ditches, Ga., Fla., in soft, muddy places (Elliott), floating (Le Conte). Scape 2 to 3' high. Oct.
10 U. minor L. Lvs. submersed, several times forked, segm. linear-setaceous, short, utriculato; scape 3 to 6 flowered; cor. ringent, upper lip ovate, emarginate, as long as the palate, lower obovate, flat, much longer than the obtuse, deflexed spur.-Pools, Can. and N. States to Wis. Plant about half the size of No. 11. Cor. gaping, pale, yellowish. Fruit nodding. Jl.
11 U. vulgaris L Lvs. capillaceous, multifid, fibrillous; vesitles numerous, small; 8t. or rhizoma very long, floating; scape simple, 5-11-flowered! spur conical, obtuse, shorter than the closed cor. lips.- In stagnant pools, U. S. and Can. Floating stems several feet long, very branching. Leaves very numerous, 1' in length. Utricles furnished with a fringed, valvato aperture, usually inflated. Scape 5-10' high, stout, arising out of the water. Flowers alternate, showy, yellow, 5-8" long, lower lip larger, with a projecting palate, striped with brown. Jn., Jl. (U. macrorhiza Le Conte.)
12 U. resupinata Green. Sts. creeping, fibrillous, rooting; lvs. linear-capillary, • erect, undivided and entire; scapes numerous, simple, 1-flowcred, with a minute clasping bract near the top; spur obtuse, cylindric, ascending, shorter than the elongated tube of the purple cor.-Muddy shores of ponds, Towksbury (Green), Plymouth and Uxbridge, Mass. (Robbins). Leaves generally numerous, 6-15" high, the bract 1' below the flower. Corolla light purple, 4" long, lips roundish, entire, remote from the spur. Jl
13 U. subulata L. Minule; 6t. fibrillous, rooting, creeping, urticulate; lvs. few and minute, among the fibrillous roots, entire, linear, petiolate, glandular-obtuse, sometimes 0 ? seape3 few, filiform, 1 to 5-(lowered; bracts ovate, clasping; pedi-cels 4 to 5 times longer than the ovate, obtuse, veined sepals; cor. upper lip ovate, entire, lower 3-lobed; spur acute oppressed to and nearly equaling the lower lip. -A minute species in springy places, Can. to Fla. and La. Scape 2 to 4' high. Lvs. 2 to 3" by 1". Fls. yellow, 3 to 4" broad. Jn.
14 U. cornuta Mx. Scape rooting, tall, erect, scaly, with 2 to 5 subsessile fls.; lvs. fugacious or 0; lower lip very broad, 3-lobed, its center (palate) very prominent, sides rerlexed, upper lobe much smaller, emarginate; spur subulate, acute, de-curved away from the cor., and of equal length.-Can. to Fla. and La., in shallow waters or mud. St. or scape 9 to 12' high. Pedicels scarcely 2 ' long in flower, 3 to 6" in fruit. Spur 4 to 4" long. Fls. large, yellow. Jn.-Aug. (U. per-sonata Le Conte.)