Herbs, annual or probably perennial, slender, weakly ascending to erect at least at ends of stems, to 65 cm tall; stems rounded to subquadrate, smooth to sharply angled and/or longitudinally sulcate, scaberulous to glabrescent. Leaves sessile; blade drying membranous, narrowly elliptic-oblong to elliptic, 10-30(-45) × 1-7(-10) mm, puberulent and/or scaberulous to glabrescent throughout or sometimes pilose along midrib abaxially, base obtuse to cuneate, apex acute to obtuse; secondary veins 2-5 pairs; stipules puberulent, hirtellous, or glabrescent, sheath 0.5-1 mm, with 5-9 bristles 0.5-2 mm, often glandular. Inflorescences terminal and in uppermost leaf axils, several to many flowered, 3-4 mm in diam.; bracts numerous, filiform, 0.5-1 mm. Calyx glabrescent; hypanthium portion obovoid, ca. 0.3 mm; lobes 2 or 4, narrowly triangular, 0.3-0.7 mm. Corolla white, rotate to shortly tubular, 0.7-1 mm, outside glabrous, pubescent in throat; lobes spatulate-triangular, ± as long as tube. Capsules ellipsoid, weakly to strongly flattened at right angles to septum, 0.6-0.9 × 0.3-0.4 mm, glabrescent, membranous and sometimes somewhat hyaline, septicidal from apex, then both valves loculicidal through septum or sometimes fragmenting; seeds brownish yellow, ellipsoid, ca. 0.5 × 0.2 mm, obtuse at both ends, with coarse rounded pits arranged in longitudinal (i.e., vertical) rows. Fl. and fr. almost year-round.