Annual or perennial, prostrate or slender, trailing or creeping herb with strong aromatic smell; stem often reddish, finely pubescent; leaves long petioled, stipules short, adnate to petioles forming sheathing leaf bases sheathing, simple, orbicular or reniform, rather broader than long, crenate, dentate, glabrous, veins prominent beneath; flowers small, sessile, white, pink or purple in simple umbels, several at a node with 2-involucral bracts, ovate, acute, hooded, beneath each umbel; calyx campanulate, teeth absent; petals 5, small, white or pink, entire, acute, often inflexed, free, valvate/imbricate; stamens 5, epigynous; ovary 2-locular, crowned with a large epigynous disk; ovule solitary, pendulous in each locule, styles 2; fruit of 2 indehiscent carpels, pendulous from summit of the carpophore, each prominantly 5-ridged, ovate to orbicular, rugose, greenish brown, mericarps compressed, 7-9 ridged.