Glabrous, erect, annual herbs. Lvs sessile; lf pairs distant along stem. Cymes terminal, several-flowered, occasionally fls solitary. Calyx deeply divided into 6-12 linear lobes. Corolla rotate; lobes 6-12, > tube, yellow. Anthers basifixed, oblong to linear, not or slightly twisted spirally after dehiscence. Style filiform, caducous; stigma deeply 2-lobed. Capsule ovoid to ellipsoid; valve margins not intrusive. Seeds numerous, minute.