INFRASPECIFIC VARIABILITY IN THE VOLATILE LEAF OILS OF CHAMELAUCIUUN-UNCINATUM (MYRTACEAE)

Variation in leaf essential oils and morphometric characters among 38 locations of Chamelaucium uncinatum were used to describe infraspecifi c diversity and geographic patterns of variation. Four chemical types were designated: citronellal, alpha-pinene or limonene dominant, or on e in which all three monoterpenes were co-dominant. The citronellal an d limonene types were geographically restricted but the alpha-pinene a nd co-dominant types were widespread. The citronellal type also demons trated higher diversity (by Shannon-Weiner index) in the oil profile t han the other types. Biochemical differentiation was not strongly para lleled by morphological differences between chemotypes; only the citro nellal-type differed morphologically from the other three types with r espect to floral bud and leaf characters. Based on biochemical and mor phological differences, and geographic localization, it was concluded that the citronellal type may represent a recently evolved ecotype of C. uncinatum. (C) 1998 Elsevier Science Ltd. All right reserved.