POLIUMOSIDE, CHEMICAL MARKER OF THE GENUS TEUCRIUM (LABIATAE), SECTION POLIUM - THE EXCEPTION OF TEUCRIUM MIDELTENSE, A SPECIES ENDEMIC TO MOROCCO

In a chemical study on the distribution of caffeic acid esters and fla vonoids in Teucrium section Polium (Labiatae) in Morocco, poliumoside, the chemical marker for this section, was found to be present in a st able manner in all the species tested, thus confirming its value as a taxonomic marker. It contrasts with other caffeic acid esters which di splay considerable variation related to environmental conditions to th e extent of disappearing or appearing during culture. T. mideltense, a n endemic species in Morocco, is an exception with regard to poliumosi de. The molecule was absent in all populations of this taxon. The resu lt is backed up by the paradoxical nature of the species, as its repro ductive characters are typical of sub section Polium and its vegetativ e characters-and especially these of the indumentum-are distinctly mar ginal with regard to sub-section Polium to which it nevertheless belon gs. Copyright (C) 1996 Published by Elsevier Science Ltd