Herbs or subshrubs. Stems quadrangular and articulated, green; roots whitish. Leaves petiolate; blades elliptic to ovate, cystoliths absent. Inflorescences dense terminal spikes; bracts and bracteoles narrow and extremely long, fimbriate. Flowers axillary, solitary or in 3's, as long as bracts; calyx deeply 5-lobed, posterior lobe similar to bracteole, 3-veined, remaining 4 lobes equal, shorter and much narrower, 1-veined; corolla white or pinkish-white, tubular, lower half cylindrical, upper half infundibular, limb short, lobes subequal, orbicular, upper pair enclosing lower lobes in flower bud; stamens 4, didynamous, inserted in middle of tube, anthers 2-thecous, thecae equal, ovoid, minutely apiculate basally, staminode 1; disk short, cupular, ovary with 6 ovules per locule, stigma included, crateriform. Capsules ellipsoid, seed bearing nearly its entire length, placentae papilliform, retinacula lacking; seeds numerous, minute, irregularly shaped.