Utricularia Utricularia vulgaris
illustration from Jakob Sturm's "Deutschlands Flora in Abbildungen"
, Stuttgart (1796)
, commonly and collectively called the bladderworts
, is a genus of carnivorous plants
consisting of approximately 233 species (precise counts differ based on classification opinions; a 2001 publication lists 215 species). They occur in fresh water and wet soil as terrestrial or aquatic species across every continent except Antarctica
are cultivated for their flowers
, which are often compared with those of snapdragons
, especially amongst carnivorous plant enthusiasts.
are carnivorous and capture small organisms by means of bladder-like traps. Terrestrial species tend to have tiny traps that feed on minute prey such as protozoa
swimming in water-saturated soil. The traps can range in size from 0.2 mm to 1.2 cm. Aquatic species, such as U. vulgaris
(common bladderwort), possess bladders that are usually larger and can feed on more substantial prey such as water fleas (Daphnia)
and even fish fry
, mosquito larvae
and young tadpoles
. Despite their small size, the traps are extremely sophisticated. In the active traps of the aquatic species, prey brush against trigger hairs connected to the trapdoor. The bladder, when "set", is under negative pressure in relation to its environment so that when the trapdoor is mechanically triggered, the prey, along with the water surrounding it, is sucked into the bladder. Once the bladder is full of water, the door closes again, the whole process taking only ten to fifteen milliseconds. Read more...