Nine species , drwn from two sections of the genus Sideritis (Labiatae) from the Canary Islands were examined. Terpenoids, sterols, flavonoids, coumarins and lignans were isolated. From the chemosystematic point of view the Sideritis species ware divided into three groups. The first was formed by S. argosphacelus and S. macrostachya, the second by S. bolleana, S. canariensis, S. candicans, S. candicans var. TFC 3890, S. dasygnaphala and S. dendrochahorra, while the third contained S. gomerae and S. cabrerae.

The authors are grateful to Professor Wildpret and Dr. P. Pérez de Paz, Botany Department, University of La Laguna, for classifying the material, and appreciate their interest in this article. We are also indebted to Professor H. W. Kircher (Univ. Arizona, USA) for a sample of campesterol.

Peer reviewed