Utricularia juncea, the Southern Bladderwort is distributed through North America, Belize, Trinidad, North Brazil, Columbia, Venezuela and Guyane. It is a terrestrial of temperate climats. A prolific terrestrial Bladderwort which spreads rapidly.
Utricularia Juncea blooms on floating carpets of vegetation. The flowers are small and yellow. The flowers are self-fertile and apparently are usually, if not always, self-pollinated. Utricularia juncea has a short purplish flower stalk. Produces a moss-like mat of bright green leaves less than 4 mm long.
The bladder-trap is unique to the Utricularia, giving them their nickname of Bladderwort. Utricularia has no true root system. They form creeping or floating, thin, hair-like stems that extended away from the main body of the plant. The bladder-traps are held on these stems. The traps are underground and are too small to hand feed. So, it has to catch it's own microscopic prey. Thin, filament-like hairs protrude from the trap door. These serve as guides to send the prey toward the door. These plants use low pressure inside the chamber vs. high pressure outside. When a bug activates the hairs, the door opens quickly, forcing the victim into the low-pressure digestion area. The water is pumped out and the mulcilage seal is re-established. The plant now secrets digestive juices to break down the captured prey and absorb the mineral rich fluid. Trapping usually occurs within 1/50 of a second. It is believed that glands found around the closed entry may also secrete an attractant that may aid in luring prey.
Hardiness zone 10, (1°C/35°F) in Winter. Utricularia juncea favour sunny locations in permanently wet open ground. In captivity, they grow well in pure sphagnum moss as well as in a standard 1:1 peat moss/sand mix. Like other carnivorous plants, they do require pure water and can be killed by fertilizer in the soil. In nature, water levels are usually near or even a little above the soil surface. Utricularia prefer frequent overhead watering, at least once a day in Summer, and once every few days in Winter.