Annual, erect, straggling herb; profusely branched, often rooting at lower nodes; leaves lanceolate or oblong, margins undulate or waved, acuminate at apex, oblique at base, charataceous, glabrous or sparsely pilose, sheaths sparsely villious, ciliate at mouth; spathes subsessile, ovate, hooded, acute 3-5, restricted at tip of branches with 1-3 smaller leaves in addition to the 2 normal leaves, upper branch of the cyme sterile, outer 2-5 flowered fertile; bluish-violet flowers; sepals 3, outer one cucullate, inner two often connate at base; petal 3, ovate, unequal, clawed, 2 larger, third one smaller, blue to violet; stamens 3-fertile, filaments glabrous, anthers oblong, one usually larger; staminodes 2, 3, 6-lobed, yellow; ovary trilocular, glabrous, ovules 1 or 2 in anterior locule, solitary or absent in posterior locule; capsules 2-3 per spathe, obovoid, trigonous, 3-celled, 2-valved with a warty, indehiscent, posterior cell; seeds shortly ellipsoid, smooth, pitted, black.