Virginia Tech Weed Identification Guide

Bladderworts: Utricularia spp.

Weed Description:  Submersed aquatic plants that float freely throughout the water and have no true roots.   Bladderworts can be found in ponds, lakes, ditches, and bogs.  Most bladderworts are free-floating aquatics, however some species may occur in marshes or along the edges of ponds, lakes, or bogs.  The bladderworts are carnivorous plants that capture aquatic invertebrates in their bladders and then break these organisms down to nitrogen and other nutrients.

Leaves:  No distinct leaves occur.  However, the stem-like segments of this species are actually the leaves.  Many distinctive bladders are attached to these segments.  When removed from the water, the bladders are almost clear and have a pinkish-red color.

Stems:  Stems may be creeping, floating, or submersed, depending on the species.  Stems are typically branching with bladders attached throughout.

Roots:  No true roots are present on the aquatic bladderwort species.

Flowers: Most bladderwort species have yellow flowers, however there are a few with either white (Utricularia olivacea) or purple (Utricularia purpurea) flowers.  Flowers occur on an erect, leafless stems (scapes) that may reach up to 6 inches in length and are usually completely emerged above the water surface.  Flowers reach up to 3/4 inch in width.
Identifying Characteristics: The bladders that occur on the stems and leaves of all the Utricularia species helps to distinguish these weeds from any other floating or submerged aquatic weeds.