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..
Aquatic herbs, with horizontal submerged stems, the branches verticillate, and verticil-lately or oppositely decompound. Leaves, at least in the adult plant, none. Bladders terminal on the ultimate branches, the mouth naked or with a single median hairy proboscis. Inflorescence racemose, 1-4-flowered; scales on the lower portion of the scape none; pedicels from the axils of bracts, without bractlets, erect in fruit. Calyx 2-lobed, the lobes herbaceous, concave. Corolla strongly 2-lipped, the upper lip not lobed, the lower lip 3-lobed, the lateral lobes saccate and together constituting a prominent 2-lobed palate, the middle lobe flat, comparatively inconspicuous. Anthers not lobed. Capsule many-seeded. Seeds tuber-culate. [Latin, vesicula, a little bladder.]
About 6 species, confined to the New World. Type species: Utricularia saccata LeConte.
Stems 1°-3° long, the internodes 1'-2' long, the primary branches in whorls of 5-7, verticillately decompound. Leaves none; bladders 1"-1 1/2" long, without bristles, the exterior surface of the valve with a central tuft of glandular hairs; scape 2'-6' high, 2-4-flowered; bracts membranaceous, basally attached, or more commonly with a free portion below the line of insertion; pedicels 3"- 4" long, half longer in fruit; calyx-lobes subequal, 1 1/2" long; corolla red-purple, the upper lip subrhom-boid, about 4" long and 6" broad, concave, the lower lip 4"-6" long and broad, with a yellow spot at the base; spur conic, appressed to and shorter than the lower lip; capsule 1 1/2" in diameter; seeds numerous, minute, tuberculate-spiny, especially toward each end.