riverweed

[riv-er-weed]

noun

any of several chiefly tropical submerged aquatic plants of the genus Podostemum and related genera, growing in rapidly moving streams.

Origin of riverweed

First recorded in 1665–75; river¹ + weed¹

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019