South African plant makes for refreshing drink (6)
I believe the answer is:
protea
'south african plant' is the definition.
(I've seen this before)
'for refreshing drink' is the wordplay.
'for' becomes 'pro' (as in being 'pro' something).
'refreshing drink' becomes 'tea' (tea is a refreshing drink).
'pro'+'tea'='PROTEA'
'makes' is the link.
(Other definitions for protea that I've seen before include "Ascend" , "S.African flowering shrub" , "South African evergreen" , "South African plant" , "S. African shrub; to pear (anag.)" .)