Growth variability of six Mediterranean taxa of the Teucrium lusitanicum Schreb. complex (Labiatae) and its systematic relationships

The growth under controlled conditions of plantlets of six taxa belonging t o the Teucrium lusitanicum Schreb. (Labiatae) complex of the Mediterranean basin was analysed. The results indicate strong proximity of the taxa of th e T. lusitanicum complex following a recent adaptive radiation. Work was ca rried out on two different substrates, making it possible to isolate the mo st discriminatory taxonomic growth parameters in relation to the characters determined by the environmental conditions. The parameters thus discrimina te between taxa with similar habitats. Among the vegetative growth paramete rs studied, the branching rate and the thickness of the indumentum were fou nd to be good discriminatory characters : (1) they differentiate T. dunense Sennen from the other taxa of complex; (2) they discriminate between the t wo intraspecific taxa of T. mairei sensu Sauvage & Vindt in Morocco (in the Rif and the Middle Atlas); two new statuses with specific rank are propose d : T. joannis and T. embergeri; (3) they slightly separate the two populat ions (coastal and inland) of T. lusitanicum; a new subspecies T: lusitanicu m subsp. clementiae from the south-eastern part of the Iberian peninsula is proposed. Found differentiations are discussed in accordance with of prese nt systematic positions of the taxa. They are equally discussed according t o their habitats.