Annual or perennial herb 10 - 25 cm tall Stem: with six to fourteen nodes and erect flowering branches, green to yellowish green, 10 - 25 cm long. Leaves: below ground or submersed, tiny, inconspicuous. Flowers: fully opening (chasmogamous), borne one to six on a flower stalk (scape), subtended by bracts with inner secondary bracts. The petals are yellow and two-lipped with a 9 - 16 mm long lower lip having a large rounded projection at the center of the lip, and the upper lip being a bit shorter and much narrower than the lower lip. Spur (extended sac at base of petals) 7 - 14 mm long, pointing downward. Fruit: a two-valved capsule containing small seeds. Roots: finely branched, having tiny bladders.
Similar species: Utricularia subulata is also a terrestrial Utricularia species with leaves that are linear or absent. It differs by commonly having flowers that remain closed (cleistogamous) and rarely having flowers that open (chasmogamous).
Flowering: early June to late October
Habitat and ecology: Very rare in the Chicago Region, growing in calcareous pannes near Lake Michigan.
Occurence in the Chicago region: native
Etymology: Utricularia comes from the Latin word utriculus, meaning "a small bottle."This refers to the insect-trapping bladders on the leaves and runners of the bladderworts. Cornuta means horn-shaped.
Lvs small, mostly subterranean, seldom seen; nodes mostly 6-14; roots finely branched, with minute bladders; flowering branches green to yellow-green, erect, straight, 10-25 cm; fls 1-6, all chasmogamous; bracts ovate, 1-2 mm, facing the axis; bractlets 2, edgewise to the axis, facing each other, oblong, acute; pedicels 1-2 mm; fls yellow, the spur 7-14 mm, directed downward, the lower lip 9-16 (avg. 13) mm, with greatly elevated palate surrounded by a spreading margin; 2n=18. Wet shores; Nf. and Que. to n. Mich. and Minn., s. to Fla. and Tex.; W.I. July, Aug. (Stomoisia c.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.