Corolla lobes above mostly white or blueish or pinkish white, bluish or mauve below, tube light green or greeny white, narrow part of tube outside with rounded minute papillae; tube slightly curved, altogether (2.1)2.3–3.1(3.4) mm. long, the dilated part ovoid-elliptic in shape, (0.8)1–1.3(1.5) x (0.4)0.5–0.8(0.9) mm., the narrow part (0.2)0.3–0.6(0.7) mm. wide; lobes (0.7)1–1.5(1.8) x (0.3)0.4–0.7(0.9) mm., ovate-triangular to ovate-oblong, not parted to the base, acute.
Leaves (23)28–39(47) x (0.5)0.7–2.5(4) mm., linear, linear-lanceolate to narrowly elliptic-lanceolate, margins and midrib beneath papillose, otherwise surfaces scabrid to glabrous, apex acute, narrowed to the base; stipular sheath (0.7)1–1.6(2) mm. long, stipular lobes (0.5)0.7–1.2(2.5) mm. long.
Annual herb, 100-300 mm tall. Flowers in subsessile or sessile pairs at nodes. Corolla tube (2.1-)2.3-3.1(-3.4) mm long, dilated part equalling narrow part in length. Flowers with lobes mostly white, bluish or pinkish white. above, bluish or mauve below, tube light green or greenish white.
Calyx tube (0.6)1–1.4(1.5) x (0.5)0.7–1.5(1.7) mm. ovoid to elliptic, densely covered with rounded papillae; lobes (0.8)1–1.4(1.7) mm. long and (0.2)0.3–0.5(0.6) mm., narrowly triangular to linear-lanceolate, margins and midrib scabrid with stiff minute papillae.
Inflorescences spike-like, many-flowered, mostly 2 subsessile flowers at a node, the flower in a fork of a dichasium distinctly pedicellate; peduncles 1–60 mm. long; pedicels (0)2–10(25) mm. long, all parts densely papillose like the stem.
Erect unbranched to sparsely branched annual herbs 10–30 cm. tall; stems ± densely papillose often reddish at base and below nodes.
Style and stigma as long as the narrow part of the tube, stigma lobes 0.7–1(1.4) mm. long, tips touching the anthers.
Capsules (2)2.2–3(3.4) x (2.8)3.4–4.3(4.7) mm., subglobose to globose, ± sparsely papillose.
Anthers ± oval, c. two thirds the length of the dilated tube; pollen 4–5-colporate.
Seeds light brown, c. 0.4–0.5 mm. long, angular-subconic.