or perennial, erect glabrous herbs. Stem more or less 4-angled. Leaves sessile
or shortly petiolate, ovate to elliptic, entire, 3-5 nerved base. Flowers in
leafy, dichotomous cymes, 4-5 merous, bracts foliaceous. Calyx deeply lobed,
enlarged and persistent in fruits, lobes dorsally keeled, winged or flat.
Corolla rotate, tube short, broadly cylindrical, lobes contorted in bud, ovate
to elliptic, acute or obtuse apex. Stamens inserted in throat of corolla,
filaments very short, dilated base, anthers 2-celled. Ovary 2-celled by
intrusion of locular wall, styles long, declinate, stigmas capitate or 2-lobed.
Capsules globose or ovoid, septicidally 2-valved. Seeds numerous, minute,