Annual or perennial herb 3-75 cm tall, sometimes rather woody and often densely tufted; stems erect or rarely decumbent or spreading. Leaves alternate or the proximal opposite, linear to narrowly ovate, (narrowly) elliptic or oblanceolate, 0.4-10 cm long, 0.1-1.4 cm wide, base cuneate to ± expanded-auriculate, margins subentire, apex obtuse to acute, apiculate, green and sparsely pubescent to silvery-grey above, white-tomentose beneath. Capitula rather few to very numerous in small to lax and diffuse terminal and upper axillary corymbiform cymes; stalks of individual capitula shortly white-hairy; involucre obconic-turbinate to campanulate-hemispherical, 2-6 mm in diameter at flowering time; phyllaries 3-4-seriate, ovate to ovate-oblong, the inner 3.5-7 mm long, acute, pungent, straight or recurving at the apex, darker green and often purple-tinged at the centre towards the apex, densely pubescent to glabrescent, scarious and shortly pectinate-fimbriate at the margins. Corolla 3.3-7 mm long, purple or violet, rarely white, lobes white-hairy with appressed hairs, 1.3-3 mm long. Achenes obconic-cylindrical or ellipsoid-cylindrical, slightly constricted towards the apex, often slightly curved, 1.2-2.2 mm long, (7-)10-ribbed, with slightly more prominent ribs alternating with slightly less prominent ribs, sparsely ascending-hairy or glabrous; pappus absent.
