Erect or prostrate herbs. Flowers 5-merous in axillary, solitary
or occasionally 2-3 superposed or in axillary triads. Bracts absent, bracteoles
foliaceous. Calyx 5-lobed, equal or unequal. Corolla funnel-shaped, lobes 5,
sub-equal, twisted to left in bud, spreading, caducous. Stamens 4, didynamous,
included, anther cells 2, oblong, equal, staminode occasionally present. Ovary
with 3-10 ovules in each cell, stigma 1- or 2-lamellate. Capsules oblong with a
basal, solid beak. Seeds orbicular, flattened, hygroscopically hairy.