Plead for type of tree around London area (7)
I believe the answer is:
beseech
'plead for' is the definition.
(thesaurus)
'type of tree around london area' is the wordplay.
'type of tree' becomes 'beech' (I've seen this before).
'around' is an insertion indicator.
'london area' becomes 'SE' (abbreviation for South East).
'beech' placed around 'se' is 'BESEECH'.
(Other definitions for beseech that I've seen before include "request, urgently" , "wood" , "Beg earnestly, plead" , "petition" , "Beg earnestly, implore" .)