Erect robust dichotomously branched annual, 2–2 1/2 feet high, somewhat scabrous with short puberulence. Branches subterete. Leaves linear-lanceolate or lanceolate-oblong, obtuse or subacute, apiculate, attenuate at the sessile base; 2/3–2 1/2 by 1/15– 1/2 in., the uppermost ones smaller; stipules shortly sheathing, 2–3-cuspidate. Flowers tetramerous, 1/2– 2/3 in. long, slender, 1–2 together, subsessile or shortly pedicellate, in pedunculate sessile terminal 2–3-chotomous cymes; branches of the inflorescence spicate in fruit. Calyx shortly pubescent in flower, 1/10– 1/8 in. long; lobes lanceolate-subulate, about as long as the tube. Corolla salver-shaped, glabrous, several times exceeding the calyx; lobes lanceolate-linear, rather obtuse (fide Klotzsch). Capsule depresso-globose, 1/8 in. long, subdidymous, puberulous or nearly glabrate, crowned with the short lanceolate persistent calyx-teeth, at length bursting at the apex loculicidally. Seeds angular, imbedded in the corrugations of the placentas.