Morphology and distribution of trichomes in Italian species of Teucrium sect. Chamaedrys (Labiatae) -- a taxonomical evaluation

Micromorphology and distribution of trichomes (both secretory and not) in different parts of plants of the five Italian species belonging to Teucrium sect. Chamaedrys have been studied. These characters neatly evidence the differences between the taxa considered; of particular interest are the observations concerning the dense coverage of peltate hairs on the abaxial face of the leaves of T. flavum subsp. glaucum and the characters contributing to a better identification of T. marum and T. subspinosum. The importance of the calyx indumentum as distinctive taxonomical character of the genus Teucrium is confirmed, stressing at the same time the necessity of completing the observations at micromorphological level.