The Leaf Essential Oils of the Australian Members of the GenusCallistemon(Myrtaceae)

The majority of Australian species (30) of the genus Callistemon gave leaf essential oils with 1,8-cineole as the major component (45–80%). Other compounds present in these species included α-pinene (2–40%, the majority being 2–8%), limonene (2–9%, the majority being 5–8%) and α-terpineol (1–13%, the majority being 5–10%). The species that produced these oils did so in oil yields of 0.1–1.0%. The species giving very low oil yields (<0.1%), viz. C. brachyandrus, C. montanus, C. polandii, C. teretifolius, C. sp. (Walsh's Pyramid P.I. Forster 13767), C. sp. nov. “Oakey,” C. pachyphyllus, as a general rule, produced oils in which the amount of 1,8-cineole was low (<20%) and generally there was a preponderance of sesquiterpenes.