Annual or perennial herb 5 - 10 cm tall
Stem: delicate, rarely longer than 10 cm, creeping and mat-forming.
Leaves: submersed, less than 0.5 cm long, usually single-forked (sometimes two), circular in cross-section, with a few bladders less than 2 mm across on the leaf segments. The leafy branches form tangled mats below the water surface.
Flowers: borne one to three on a stalk (scape) less than 1 mm thick, yellow petals are two-lipped with upper lip and lower lip about the same size (5 - 6 mm long) and a rounded projection in the center. The spur (extended sac at base of petals) is thick, half as long as lower lip, and blunt to rounded at the tip.
Fruit: a two-valved capsule containing small seeds.
Similar species: Utricularia radiata, Utricularia intermedia, Utricularia minor, Utricularia macrorhiza, and Utricularia geminiscapa are other aquatic or amphibious Utricularia species with dissected leaves. The flower stalk of Utricularia radiata has a whorl of leaves with inflated petioles. Utricularia intermedia and U. minor have flat leaf divisions. Utricularia macrorhiza has flower stalks that are thicker than 1 mm, inflorescences with more than four flowers, and leaves with bladders larger than 2 mm across. Utricularia geminiscapa rarely has emersed flower stalks with flowers that open (chasmogamous), but often has submersed non-opening flowers (cleistogamous). It also forms a fine mass of floating leaves.
Flowering: early July to mid September
Habitat and ecology: Rare in ponds, muck flats, bogs, low swales, and along shores of lakes.
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. Gibba means swollen.
Author: The Morton Arboretum
