Berry Snr (5)
I believe the answer is:
elder
'berry' is the definition.
The definition and answer can be both plants as well as being singular nouns.
Maybe there's an association between them I don't understand?
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for elder that I've seen before include "senior church member" , "Tree - wise counsellor" , "Patriarch" , "Senior churchperson" , "Tree and Mormon church officer" .)