Annual, erect, scabrid herb, simple or branched, 10-20 cm in height; leaves lower opposite, upper mostly alternate, sessile, linear, sometimes reduced to scales; flowers axillary, solitary, often forming terminal, interrupted spikes, bracts linear to subulate, pubescent, lower bracts foliaceous, often longer than calyx; bracteoles-2, linear; calyx tubular, hispid, pubescent at the curve, 5-15 ribbed, 5-toothed, lengthening in fruit; corolla white or with pale pink throat, pilose, tube slender. abruptly incurved at about the middle of throat limbs spreading, 2-lipped, upper lip shortly notched, lower 3-fid; stamens-4, didynamous, included, anthers 1-celled, dorsifixed, base obtuse, ovary 2-celled; style thickened above, stigma simple; capsules included in calyx, ovoid or subglobose, apiculate, loculicidal, valves entire, separating from the placentae; seeds many, ovoid, oblong, reticulate.