a fern, Thelypteris palustris, having pinnatifid fronds and growing in wet places.
Origin of marsh fern
First recorded in 1855–60
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
a fern of marshy woodlands, Thelypteris palustris, having pale green pinnate leaves and an underground rootstock
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012