Forest denizens (5)
I believe the answer is:
trees
'forest denizens' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for trees that I've seen before include "Elms, pines etc" , "Tall, perennial, woody plant" , "Elders perhaps" , "''I see ... of green / Red roses too'' (What a Wonderful World)" , "Woods" .)