Triadenum Rafin.

Perennial herbs, glabrous with pale or black glands. Leaves opposite, entire. Inflorescence terminal and axillary cymes. Flowers bisexual, 5-merous. Sepals 5, quincuncial. Petals 5, white (in Indian species), imbricate, deciduous. Stamens in 3 fascicles (2 + 2 + 1), 1 antipetalous and 2 antisepalous, persistent, stamens 3 in each fascicle, with slender filaments ca 1/3 connate at the base; anthers versatile, with a pale gland on connective; staminodes absent; sterile fascicles (hypogynous scales) 3, alternating with fertile fascicles, entire, scale-like (in Indian species). Ovary trilocular with many ovules on axile placentation; styles 3, free, slender; stigmas capitate. Capsules septicidal with vittae. Seeds carinate, testa reticulate-pitted; embryo slender, straight with distinct cotyledons.

Temperate regions of Asia, Russia(Eastern Siberia), Eastern North America, Canada, ca 6 species; one in India.

List of Lower Taxa