By all conclusions two or three turn over a new leaf? (7)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

Last letters, respectively, of ( all conclusions ) “ two or three ” plus ( By … ) GO(a turn/an opportunity to do something that comes periodically) containing ( over ) [ A + N(abbrev. for “new”) ]. Defn: A plant identified with/synonymous with its leaf or leaves.