Wetland plants (5)
I believe the answer is:
reeds
'wetland plants' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for reeds that I've seen before include "Tall water grasses on lake shore" , "Tall slender grasses of wet areas" , "Tall grasses with hollow stems" , "Stems for pens" , "Music-makers" .)