Utricularia gibba

Utricularia gibba, commonly known as the humped bladderwort or floating bladderwort, is a small, mat-forming species of carnivorous aquatic bladderwort. It is found on all continents except Antarctica.

U. gibba has an exceptionally small genome for a plant, despite having a typical number of genes. The sequencing of its DNA revealed only 3% repetitive DNA material.

Description

Utricularia gibba is an aquatic carnivorous plant that belongs to the genus Utricularia, or bladderworts. The specific epithet gibba is Latin for "hump" or "swelling" – a reference to the inflated base of the lower lip of the corolla. It is a small- to medium-sized aquatic plant that can either be affixed to the substrate in shallow water or free-floating in the water column, however it will likely flower more if supported by a substrate beneath shallow water. It forms mats of criss-crossing, branching, thread-like stolons, each growing to approximately 20 cm (8 in) or longer and 0.2–1 mm thick. What are sometime described as leaves or leaf-like organs – the actual distinction is difficult in the reduced morphology – are numerous and scattered along the length of the stolons and are 0.5–1.5 cm (0.2–0.6 in) long with a very short dichotomous branching pattern toward the tip of anywhere from one to eight branches but usually not more than four. The bladder traps take the place of some of these distal branches on the leaf-like structures. The traps are ovoid and are attached to the leaf-like structure by a short stalk; each trap is 1–2.5 mm long and has two primary setiform branched appendages on top and some smaller appendages surrounded the entrance to the trap. The appendages are the trigger that sets the trap off and vacuums the prey that touched it into the bladder to be digested.