CHEMICAL VARIABILITY OF THE ESSENTIAL OIL OF TEUCRIUM-PUECHIAE GREUTER AND BURDET ON THE LANGUEDOCIAN COAST (FRANCE)

The composition of the essential oil of Teucrium puechiae Greuter and Burdet (Lamiaceae), shows no essential oil plasticity and, on the othe r hand, a very low chemical polymorphism. This small intrapopulational qualitative variability is probably the result of an adaptation to th e environmental variation in Languedoc (French Mediterranean coast). H owever, the mode and growth rate, connected to the perturbations in du ne ecology, have an effect on the quality of the essential oil. The na tural selection seems to act upon the quantitative proportional aspect of the essential oil in seedling and young plants, by favouring the p recocious elaboration of sesquiterpenes (terminal products).