or perennial herbs, occasionally twinners or shrubs. Leaves opposite or
rosettes, entire, exstipulate. Flowers in 2-3 chotomous, terminal, paniculate
or axillary cymes, 4-5 merous, bracts foliaceous or absent. Flowers regular or
irregular, hermaphrodite. Calyx persistent, tube campanulate, lobes imbricate.
Corolla gamopetalous, rotate to infundibular, lobes contorted. Stamens as many
as corolla lobes, inserted on throat or tube of corolla, filaments filiform or
dilated at base. Disc absent, occasionally annular, entire or lobed. Ovary
superior, sessile, 1-locular, styles simple, stigmas 2-lobed. Fruit a capsule,
septicidally 2-valved or indehiscent. Seeds angular or globose, rarely
compressed, occasionally narrowly winged.