Exotic scarab is in plant (8)
I believe the answer is:
brassica
'in plant' is the definition.
'brassica' can be an answer for 'plant' (I've seen this before). I'm not certain of the 'in' bit.
'exotic scarab is' is the wordplay.
'exotic' indicates anagramming the letters.
'scarab'+'is'='scarabis'
'scarabis' with letters rearranged gives 'BRASSICA'.
Can you help me to learn more?
(Other definitions for brassica that I've seen before include "Cabbage, say" , "Plant genus including many vegetables" , "Cabbage, broccoli, etc." , "Vegetable" , "Plants such as cabbage and brussels sprouts" .)