Herbs, shrubs or trees; leaves usually opposite or whorled, simple, mostly entire, stipules minute or commonly absent; flower bisexual, generally actinomorphic, cleistogamous flowers present in some genera, perigynous, an hypanthium present and sometimes subtended by an epicalyx of connate pairs of bracts, the sepals commonly 4, 6, or 8, valvate, seemingly marginal on hypanthium, the petals of same number as sepals or absent, seemingly distinct and arising from rim or upper inner surface of hypanthium, alternate with sepals, crumpled in bud, imbricated, often fugacious, stamens usually twice as many as petals, in 2 whorls, those of outer whorl alternate with petals and emerging from hypanthium some distance below them, th anthers 2 celled, introse, dorsifixed, dehiscing longitudinally, pistil 1, the ovary superior, sessile the locules and carpels usually 2-6, the placentation typically axile, the ovules several to numerous on each placenta, stigma usually discoid or capitate, fruit a various dehiscing capsule, seeds with a straight embryo, the endosperm lacking.