Erect annual or short-lived perennial, sometimes rather woody, herb 90-300 cm tall; unpleasantly aromatic (smelling of tom-cats when fresh); stems shortly sericeous-pubescent or tomentose. Leaves narrowly ovate or narrowly obovate, 5-17 cm long, 0.8-3 cm wide, base cuneate, apex acute, whitish or greyish with rather dense silky pubescence especially beneath, somewhat glabrescent above. Capitula congested in dense terminal and upper axillary compound cymes; stalks of individual capitula 0.5-7 mm long, very densely ascending-pubescent; involucre hemispherical, 2-3.5 mm long; phyllaries 2-3-seriate, very pale green with darker green or purplish central area towards the apex, narrowly ovate, 3 mm long, glabrous except for ciliate margins, often glandular, with scarious often purplish tips. Corolla white or pale mauve or lilac to mauve, purple, blue-purple or bright blue, 2.2-3.2 mm long, glandular, limb infundibuliform, lobes 1-1.4 mm long. Achenes 1-1.8 mm long, 2-3(-5)-ribbed, especially the outer often somewhat curved, the two lateral ribs rather prominent and often somewhat wing-like, with a short apical rim or shallow cup.
