Irritates plants (7)
I believe the answer is:
nettles
I believe this is a double definition.
'irritates' is the first definition.
('nettle' can be a synonym of 'irritate')
'plants' is the second definition.
The answer is an example.
(Other definitions for nettles that I've seen before include "Irritates" , "One acting Chief Inspector on TV" , "Plants with stinging hairs" .)