Annual herb, erect, to 35 cm high, hispid to glabrous, including calyx. Stem scapiform. Leaves linear to narrowly elliptic or lanceolate, rarely ovate, 2–90 mm long, 1–12 mm wide; margins usually lined with a pale band of cells. Flowers terminal and axillary, in dense or lax simple and compound umbellate clusters, rarely solitary; pedicels to 32 mm long. Calyx campanulate; tube 1–2 mm long; lobes 1–4 mm long, acute, attenuate or pungent. Corolla white, in dried specimens often orange-striate; tube 4.5–10 mm long; lobes 1.1–3.5 mm long. Stamens 2.9–5.7 mm long; filament bases swollen, white-pilose; anthers obtuse; dehiscence extrorse. Capsule globular to ellipsoidal, 2.5–4.5 mm long; fruiting style 1.5–5 mm long.