Right working for ambassador to collect flower (5)
I believe the answer is:
rhone
'flower' is the definition.
(River Rhone, something which flows)
'right working for ambassador to collect' is the wordplay.
'right' becomes 'r' (common abbreviation).
'working for' becomes 'on' (I can't justify this - if you can you should believe this answer much more).
'ambassador' becomes 'HE' (His or Her Excellency).
'to collect' indicates putting letters inside (inserted letters are collected by others).
'on' going within 'he' is 'hone'.
'r'+'hone'='RHONE'
Can you help me to learn more?
(Other definitions for rhone that I've seen before include "River of Switzerland and France" , "French flower" , "department" , "River running through the city of Arles" , "Camargue river" .)