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.
Author: The Morton Arboretum
From Flora of Indiana (1940) by Charles C. Deam
This is one of our rarest species. It has been found only in St. Joseph, Elkhart, and Lake Counties. It was formerly common on the wet, sandy borders of sloughs near Lake Michigan in Lake County.
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.