Climbing plant with bright flowers (8)
(Other definitions for sweet pea that I've seen before include "A wee pest on fragrant climbing plant" , "Peseta we paid for climbing garden flower" , "Climbing garden plant - saw tepee (anag)" , "Highly-scented garden climber" , "Climbing plant with butterfly-shaped flowers" .)
(Other definitions for sweetpea that I've seen before include "climbing plant" , "climber" .)