Boronia is among the most expensive perfumery materials in the world. It grows only in Tasmania, yields almost nothing, and smells of violets, raspberries and hay at once. Ionones do that, formed when the flower breaks down its own carotenoid pigments.^[1] They are the same compounds that make violets smell of violets. Reviews note ionones have roles beyond scent, including protecting cells, though boronia itself is bought for the smell.^[2]