Stem terete, with short internodes and usually 2 branches at each node, or stem sparsely branched, pilose with spreading ± crisped hairs intermixed with multicellular gland-tipped hairs; branches 10–33 cm long, slender, ascending or sometimes procumbent.
Calyx narrowly campanulate with (4)5 deltoid lobes, hispid and ciliate with antrorse hairs and sometimes intermixed with pilose gland-tipped hairs; calyx tube 2–3 mm long; lobes 1–2 mm long.
Corolla white, cream, pink or mauve, tubular-infundibuliform; tube c. 4 mm long, lobes c. 1 mm long, rounded.
Filaments 1–2 mm long, glabrous; anther thecae c. 0.3 mm long, unequal, divaricate, inverted, tailed.
Flowers in groups of 2–3 in each leaf axil, or solitary in upper axils; pedicels 0.3 mm long.
Seeds 2, oblong, foveolate, with the foveoles in longitudinal rows.
Ovary 2-locular with 1 ovule per locule; style 2 mm long, filiform.
Erect, slender or bushy, annual herb up to 45 cm tall.
Fruit 2 mm long, obovoid.