Yellow-flowered plant related to the monkey flower (4)
I believe the answer is:
musk
(Other definitions for musk that I've seen before include "Perfume substance" , "Scented glandular secretion from a deer" , "Scent (for a stag party?)" , "16 21 [INDIAN IMPORT]" , "Strong-smelling secretion used in perfumery - type of melon" .)