Rose oil the aromatics unaltered by heat. Because CO is gas at normal atmospheric pressure, it leaves no trace of itself in the final product. The equipment for CO extraction is expensive, which is reflected in the price of the essential oils obtained from the process. It takes a large amount of rose petals to distill a small amount of essential oil. Depending on extraction method and plant species, the typical yield can be approximately 1:3,000. To mitigate the cost, some dishonest dealers will dilute rose oil with geranium ("Pelargonium graveolens") or palmarosa ("Cymbopogon martinii") essential oils, both of which are rich
Eriocephalus africanus are not related. "Eriocephalus africanus" is fragrant, with lightly felted foliage that gives the plant a matt silvery appearance. The inflorescences are small brown and pale yellow heads borne in corymbs; each head bears a few bisexual disk florets with abortive ovaries and snowy white petals that practically cover a bush in flower. The disk florets surround usually some four to eight female florets in the centre. Ecologically the plant is important to many insects as a source of nectar and pollen, and as a minor browse to flocks and antelope. Essential oil derived from "E. africanus" is used as