Species Information

Water chestnut (Trapa natans) Water chestnut (Trapa natans)
Petroglyph
Water chestnut (Trapa natans)
Petroglyph
Water chestnut
Trapa natans

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History
  • Introduced to U.S. before 1879 by a gardener in Cambridge, Massachusetts, who planted it in several ponds
  • Native to warm temperate regions of Eurasia

Characteristics
  • Rooted, annual, aquatic plant with submerged and surface leaves
  • Surface leaves are waxy and triangular with toothed edges
  • Submerged leaves are feathery and whorled around the leaf stalk
  • Stems can grow up to 16 ft (4.8 m) long
  • Forms dense, floating mats
  • White flowers
  • Nut-like fruit with 2-4 spines

Habitat
  • Lakes, ponds, slower sections of rivers and streams
  • Prefers nutrient-rich water with a neutral to slightly alkaline pH
  • Can grow in water up to 16.5 ft (5 m) deep, but prefers shallow water (1-6.5 ft, 0.3-2.0 m)

Known Distribution in the Northeast
  • Connecticut, Massachusetts, New Hampshire, New York, Quebec, Rhode Island, Vermont

Impacts
  • Dense, floating mats restrict light availability, reduce the oxygen content, and displace other emergent and floating vegetation
  • Impedes boating, fishing, swimming and other recreational activities

 


Water chestnut (Trapa natans)
USFWS
Water chestnut (Trapa natans)
Water chestnut (Trapa natans)
Water chestnut (Trapa natans)