Utricularias (pronounced “you-trick-you-layrias”), commonly called bladderworts, are more than 200 species of carnivorous plants that grow on wetlands and in freshwater, and are found virtually worldwide except for Antarctica.
Some are cultivated for their exotic flowers, often compared to members of the pea family, snapdragons and orchids. Bladderwort flowers are usually bright yellow or occasionally white, pink or lavender, and have two “lip-like” petals of about equal size. Flowers are on long stalks that emerge several inches above the water.
Bladderworts are rootless, and have main stems from which lacy or scale-like leaves grow. Bladders are attached at regular intervals along the linear leaf segments.
All bladderworts are carnivorous and capture small organisms by means of bladder-like traps. Wetland species tend to have tiny traps that feed on microscopic organisms. Free-floating bladderworts usually have larger bladders and feed on larger prey like small worms, water fleas and even fish fry, mosquito larvae and young tadpoles.
Some bladderworts have passive traps but many have active traps similar to a Venus flytrap, only much smaller. The prey brush against trigger hairs connected to the trapdoor. When the trap is triggered by movement of its victim along with the water surrounding it, is sucked into the bladder. Once the bladder is full of water, the door closes. The whole process takes only a tiny fraction of a second. These bladder traps are recognized as one of the most sophisticated structures in the plant kingdom by botanists.
Dozens of bladderworts make their home in the United States and species are found in both Alaska and Hawaii. With native 14 species of bladderwort each, Florida and Rhode Island have the greatest variety of any state. Seven Florida natives are commonly found floating in lakes and ditches. Four are native to our pine flatwoods.
One Florida native, humped bladderwort, is considered an invasive species of international concern in other parts of the world.
In traditional medicine, bladderwort was a remedy for urinary tract disorders including kidney stones and urinary tract infections; digestive spasms, fluid retention, and swelling. They were thought to stimulate the gallbladder and promote weight loss. Bladderwort was sometimes applied directly to the skin for burns and swelling
For an online key to the bladderworts of Florida, visit http://www.dep.state.fl.us and search for bladderwort.