Sobre la variabilidad infraespecífica de Sideritis fruticulosa Pourr. (Labiatae)

The taxonomy, nomenclature, chorology and phytosociology of Sideritis fruticulosa (Labiatae) are reviewed. We propose the division of this taxon in four subspecies (subsp. fruticulosa, subsp. cavanillesii, subsp. ferreriana, and subsp. tarraconensis), one of which (subsp. ferreriana) is described in this paper. Besides, a new variety is proposed: S. fruticulosa subsp. cavanillesii var. illerdensis. The name Sideritis ×llenasii is lectotypifie