Utricularia

These hardy and tender, aquatic and terrestrial perennials are commonly called Bladderworts. The aquatic kinds are found throughout the U.S., Nova Scotia, Europe, Asia and southern Canada. These plants produce finely divided, submerged leaves. They also produce small, bladder-like structures underneath the water, which are fitted with little valves that only open inward. They are covered with touch-sensitive hairs that allow insects, small crustaceans and fish to be trapped inside for digestion by the plant. They bear pretty purple or yellow flowers that are ordinarily held out of the water, but are sometimes supported by a whorl of spongy, floating leaves. Temperate species overwinter by buds that float to the bottom of the pond. The terrestrial kinds have lance-shaped leaves which grow up to 6 inches long. Thin flower stalks topped with racemes of yellow, purple, or blue flowers are produced.

Pot Cultivation

The aquatic types need still, shallow water that is preferably slightly acidic. The terrestrial kinds need to grow in equal parts of fibrous peat, broken bricks and sphagnum moss. Keep a bell jar over the pots and set in saucers of water, in a shady position in the greenhouse. Provide ventilation every morning by tilting the jar a few inches. Give plenty of water during the summer, but through the winter, only moisten when the compost begins to dry.

Propagation

Seeds can be sown on the surface of damp peat moss and sand and covered with a bell jar until large enough to pot separately.