Variation in Volatile Leaf Oils of the Tasmanian Eucalyptus Species II Subgenus Symphyomyrtus

Volatile oils were analysed from juvenile and adult leaves collected from natural populations of all eucalypt species from the informal subgenus Symphyomyrtus (genus Eucalyptus) native to the island of Tasmania. Four species were from the series Ovatae (Eucalyptus barberi, E. brookeriana, E. ovata, E. rodwayi) and 13 were from the series Viminales (E. globulus ssp. globulus, E. vernicosa, E. subcrenulata, E. johnstonii, E. viminalis ssp. viminalis, E. dalrympleana ssp, dalrympleana, E. rubida, E. gunnii, E yorker, E. morrisbyi, E. urnigera, E. perriniana and E. cordata). Oil yields (1.4- 5.1 % dry wt) from juvenile leaves are either similar or higher than from corresponding adult leaves (0.8-5.3% dry wt). Volatile leaf oils of the majority of species are rich in the monoterpenoids 1,8-cineole and α- pinene, while some species are rich in the monoterpenoid p-cymene and/or sesquiterpenoids spathulenol and globulol. Multivariate analyses indicated that the majority of the Tasmanian eucalypt species from subgenus Symphyomyrtus are poorly differentiated on volatile leaf oil composition. The chemical composition of volatile oils of juvenile and adult leaves were qualitatively similar, but quantitatively different in some oil components for some species.