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water hyacinth

noun
  1. a floating aquatic plant, Eichornia crassipes, of tropical lakes and rivers, that grows so prolifically it often hinders the passage of boats.

Origin of water hyacinth

An Americanism dating back to 1895–1900
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
British Dictionary definitions for water hyacinth

water hyacinth

noun
  1. a floating aquatic plant, Eichhornia crassipes, of tropical America, having showy bluish-purple flowers and swollen leafstalks: family Pontederiaceae. It forms dense masses in rivers, ponds, etc, and is a serious problem in the southern US, Australia, and parts of Africa
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