Capitula small, solitary and sessile or subsessile, or in racemes, heterogamous, discoid. Involucre subhemispheric; phyll. subequal, in c. 2 series, margins scarious, receptacle nude. ♀ exterior in several rows, fertile, with minute tubular corolla. Florets of disk few, perfect, ± campanulate. Anthers obtuse at base, style-arms of perfect florets truncate. Achenes bluntly 3-4-ribbed; pappus 0. Annual to perennial herbs with alt. lvs. A genus of some 15 spp., mostly of Chile, but a few in Madagascar, tropical Asia, Australia. The N.Z. sp. widespread, doubtfully indigenous.

Annual or facultatively perennial herbs, glandular and aromatic. Leaves alternate, cauline, sessile, toothed to entire, glandular-punctate, glabrous to densely cottony. Inflorescences mostly terminal and solitary, but appearing axillary by sympodial growth of subtending shoots, rarely racemose or truly axillary. Capitula heterogamous, sessile to shortly pedunculate, globular, biconvex, hemispherical, cup-shaped or campanulate; involucral bracts in c. 2 rows, herbaceous, scarious-margined; receptacle slightly concave to distinctly convex, glabrous, epaleate, with pithy tissue present to some degree below surface; outer florets female, corolla tubular, narrowed above and minutely 3-lobed, lobes very short relative to tube, acute to rounded, style branches linear, glabrous; inner florets bisexual, corolla funnelform, 4-lobed, lobes triangular, from half to almost as long as tube; both corolla types with scattered short vesicular trichomes (appearing as glistening sessile resin droplets); anthers shortly tailed, lacking apical appendages, or with short ovate apical appendages, anther collar not strongly differentiated, tapering evenly from filament to anther base, c. 0.05 mm long, style branches oblong, broadly rounded and papillose apically. Cypselas of female and bisexual florets similar, clavate to cylindric, 4-6(-16)-ribbed, mostly with a swollen, pithy or spongy apical portion; glandular trichomes generally present between ribs, eglandular hairs usually present along ribs, acute and straight or tightly inrolled at the apex; pappus absent. Carpopodium absent.

Annual or perennial herbs, taprooted and sometimes rooting at nodes. Lvs simple, entire or toothed, alternate. Capitula axillary or terminal, sessile or shortly pedunculate; involucral bracts in 2 rows, with membranous margins. Receptacle hemispheric; scales 0. Outer florets ♀, in several rows, tubular, yellowish; inner florets ☿, tubular. Achenes all similar, obpyramidal, square in section, distinctly 4-ribbed, with scattered glandular hairs on faces; ribs blunt, hairy; pappus 0.