Cite rose variety that's obscure (8)
I believe the answer is:
esoteric
'obscure' is the definition.
(requiring specialist knowledge or special interest)
'cite rose variety' is the wordplay.
'variety' indicates anagramming the letters.
'cite'+'rose'='citerose'
'citerose' with letters rearranged gives 'ESOTERIC'.
'that's' acts as a link.
(Other definitions for esoteric that I've seen before include "Intelligible only to the initiated" , "Taught to a select few" , "Private, confined to a select group" , "Highly specialised" , "Understandable by only an enlightened inner circle" .)