A tree for Mr. Atkinson (5)
I believe the answer is:
rowan
'a tree' is the definition.
(type of tree)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for rowan that I've seen before include "Mountain-ash" , "ash native to mountain regions" , "Tree bearing bright red berries" , "Man" , "-- Williams, theologian" .)