Annual, marshy, suberect or prostrate herb; stem glabrous, sub-succulent; leaves alternate, sessile, membranous, linear to oblong, coarsely dentate or serrulate, semi amplexicaul or dilated at base; acuminate at both ends; heads compound, sessile, globose, axillary, containing several, 1-flowered, simple heads, subtended by 2-leafy; involucral bracts, outer larger, broadly ovate-orbicular, slightly winged on back, inner linear, lanceolate; corolla white or violet, glabrous, campanulate, 5-fid; stamens-5, epipetalous, syngenecious, anthers base sagitate, tails branched; ovary 1-celled, 1-ovuled, solitary, basal, obtuse, style arms short, linear, cuneate, subtruncate; achenes included in laterally compressed bracts, about 3 mm long, dark brown, ribbed or winged shortly, hairy at the top; pappus scales absent.