Greater Bladderwort

Greater Badderwort, Common Bladderwort

Utricularia vulgaris

Utriculari vulgaris
Greater Bladderwort Jacob’s Pond, Norwell, MA July 2014


  • Clade: Eudicots/asterids
  • Order: Mint
  • Family: Bladderwort (Lentibulariaceae)
    • 300 species worldwide
    • 3 genera worldwide (Genlisea, Pinguicula, Utricularia)
    • 2 found in North America ( Pinguicula, Utricularia)
    • Polyompholxy and Biovularia are now reclassified as part of the genera Utricularia)
  • Genera: Utricularia
  • Species: Utricularia vulgaris


  • 1/2-3/4″
  • yellow
  • raceme: flowers are attached to main stem by a short stalk
  • 2-lipped snapdragon/figwort shaped flower
  • bilaterally symmetrical
  • bisexual (both male and female parts)
  • 5 united petals
  • ovary is superior with 2 carpels fused into a single chamber


  • capsule derived from the ovary

Flower Stalks

  • 4-24″ stalk  that extends above the water surface
  • tall stems provide separation between carnivorous portion and the flower that needs to leave pollinators unharmed
  • leafless

Special Adaptations

  • 6-8 floating leafstalks underwater
  • leafstalks are inflated to add buoyancy
  • leaves repeatedly branch  into hair-like appearance


  • May-September (more often June-August)


  • the swollen air bladders under the water’s surface take in tiny prey
  • Prey: mosquito larvae, water fleas, rotifers, nematodes, fish fry
  • when sensory hairs adjacent to bladder pore ,are triggered by prey a trapdoor opens to suck prey and surrounding water into the inflated submerged leaves due to negative pressure inside
  • trapdoor opens and closes within 1/460th of a second
  • larger prey may get caught in the door and be taken in little bits at a time
  • enzymes digest prey


  • ponds, bogs, bays, marshes, and other still or slowly moving waters


  • widespread
  • Alaska to Atlantic Canada and down to Mexico

Similar Species

  • Swollen bladderwort Utricularia inflata can be distinguished by prominant leafstalks arranged like a wheel at the water’s surface  (Range: Native to Eastern North America)
  • Purple Bladderwort Utricularia purpurea
  • May also be confused with watermilfoils

Please report your Swollen Bladderwort Sightings by adding a marker to our Swollen Bladderwort range map.

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Biodiversity Exposed