The genus Lavandula is known since classic antiquity as aromatic and medicinal. These characteristics are due to compounds synthesized and accumulated in secretory structures. In Portugal, we find several species of the genus including the L. pedunculata species. In this species, it is possible to distinguish between protective and secretory trichomes. With this work we pretend study the ontogeny of the types of trichomes and plantlets along their development, under different photoperiod conditions, 16 hours light/8 hours dark and 12 hours light/12 hours dark, respectively. Cotyledons and leaves from plantlets along different development were collected and used for scanning electron microscopy. The results demonstrated that in the conditions used the rate of germination of this species was low. Also this study showed that there are variations in plant development under different photoperiod in relation to the number of leaves, dimensions, density and types of the trichomes present.

Relatório de Estágio de Iniciação à Investigação Científica /ISA - Centro de Botânica Aplicada à Agricultura