Birches and beeches (5)
I believe the answer is:
trees
'birches and beeches' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for trees that I've seen before include "Large plants" , "Long lock of hair" , "Components of forest" , "Steer into the plants" , "''I see ... of green / Red roses too'' (What a Wonderful World)" .)