Trees’ leaves screening finer branches (8)
I believe the answer is:
conifers
'trees'' is the definition.
(conifer is a kind of tree)
'leaves screening finer branches' is the wordplay.
I cannot really see how this works, but
an anagram of 'finer' is 'nifer' which is within the answer.
'leaves' could be 'cos' (cos lettuce leaves) and 'cos' is present in the leftover letters.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for conifers that I've seen before include "Pines, firs, cypresses" , "Evergreen trees" .)