This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol3", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Utricularia minor L. Sp. Pl. 18. 1753.
Stems creeping on the bottom in shallow water, 4'-12' long, sparingly branched. Leaves alternate, with few divisions, usually only 1/2"-1 1/2" long, and bearing 1-5 bladders each; larger blad-derless leaves, 1"-3" long, with flat segments, sometimes occurring on special branches or segments of the main stem; scapes solitary, filiform, 2'-6' high, 3-6-flowered, with 2-5 minute auriculate scales; pedicels capillary, 1"-4" long, recurved in fruit; calyx-lobes about i" long; corolla pale yellow, the upper lip minute, 1"-2" long and half as wide, the lower 2"-4" long, the palate nearly obsolete; spur very short and saccate; capsules about \" in diameter.
In shallow water, circumpolar, southward in America to Connecticut, New York, Pennsylvania, Ohio, Indiana, Colorado and California. June-July. Often propagated by winter-buds.
Utricularia geminiscapa Benj. Linnaea 20: 305.
Stems about 8-10' long, floating horizontally beneath the surface of the water, sparingly branched. Leaves alternate, about 10" long, 4-7-dichotomous, and bladderless, or more or less reduced and bladder-bearing; scape slender, 2'-5' high, 2-5-flowered, without scales; cleistogamous flowers solitary on short peduncles, 1 at the base of the scape and others scattered along the stems, often in pairs; pedicels of conspicuous flowers 2"-3" long; corolla yellow, 3" long or more, the lower lip longer and broader than the upper, 3- lobed, with a prominent palate; spur a little shorter than the lower lip, obtuse.
In shallow water, New Brunswick to Virginia. Hooded or horned milfoil. July-Aug.
Utricularia macrorhiza LeConte, Ann. Lyc. N. Y.
1: 73. 1824. U. vulgaris var. americana A. Gray, Man. Ed. 5, 318. 1867.
Stems 1°-3° long, floating horizontally beneath the surface of the water, sparingly branched. Leaves alternate, 3/4'-2' long, dichot-omous at the base, each ray pseudo-pinnately divided, bladder-bearing, the bladders sometimes 2" long; scape stout, 3'-24' high, 6-20-flowered, with 1-5 auriculate scales; pedicels 3"-8" long, becoming 5"-10" long and recurved at maturity of fruit; corolla yellow, 7"-10" long, the lower lip a little longer and much broader than the upper, with a spreading, undulate, slightly 3-lobed border, and a prominent palate; spur shorter than the lower lip, subulate, upwardly curved, acute or obtuse.
In stagnant water or sluggish streams, Newfoundland to Yukon, south to Maryland, Missouri, Oklahoma, Arizona, and Lower California. May-Aug. Often propagated by winter-buds. Very variable, but appears to differ constantly from the related and equally variable European species, Utricularia vulgaris L., by the longer stems, the shape and direction of the spur, and the minuteness of the appendages (rudimentary stolons) at the base of the scape.