Annual to perennial herbs. Stems winged. Hairs soft and multicellular, or cobwebby, sometimes papillate. Lvs alternate, sessile or cuneate at base, simple, dentate to pinnatisect; lobes and teeth spine-tipped. Capitula homogamous, cylindric to ovoid, globose, obconic or hemispheric, solitary or in clusters. Involucral bracts in several series, lanceolate to linear, evenly tapered or with a narrow claw and broader limb; hairs papillate, cobwebby, or 0; outer bracts usually spine-tipped. Receptacle flat; scales numerous, setaceous. Florets ☿, all tubular. Corolla glabrous, 5-lobed, usually purple, rarely pink to white. Anthers acute at apex, with basal appendages 0.5-1.5 mm long; filaments ciliate or papillate. Style branches linear, erect, appressed. Achenes obovoid, weakly flattened, glabrous, smooth; achene insertion basal; pappus hairs in several rows, soft or ± stiff, silvery or sordid, scabrid, united at base into a ring.