A flower in Asia some find useful (5)
I believe the answer is:
indus
'a flower' is the definition.
(Indian river)
'some find useful' is the wordplay.
'some' indicates a hidden word (some parts of the word are used).
'INDUS' is hidden within 'find useful'.
'in asia' is the link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for indus that I've seen before include "River of Southern Asia" , "River rising in Tibet" , "9 of Pakistan" , "River of India/Pakistan" , "running water" .)