Aroma of nettle (7)
I believe the answer is:
This clue is a double definition.
'aroma' is the first definition.
(incense is a kind of aroma)
'nettle' is the second definition.
(I've seen this before)
'of' is the link.
(Other definitions for incense that I've seen before include "Get under someone's skin" , "Substance burning in a censer" , "Provoke" , "that may be used in service" , "Perfume - madden" .)