Herbs or undershrubs. Leaves alternate or
opposite, entire, simple, acute. Flowers in short terminal racemes or cymes,
regular, 5-merous, blue. Calyx divided nearly to base, segments lanceolate.
Corolla widely campanulate, subrotate, lobes imbricate. Stamens 5, attached to
short corolla tube, alternate with lobes, filaments filiform, anthers
sagittate. Ovary 2-celled, ovules many, styles 2, distinct, stigmas capitate.
Capsules globose or ovoid, septicidal or irregularly 4-valved. Seeds minute,
numerous, longitudinally ribbed.