258 genera, 6970 species; herbs, shrubs, or trees; stems often square in cross-section; often with iridoids and phenolic glycosides
Distribution
cosmopolitan
Floral characters
inflorescences with indeterminate main axis and determinate (cymosely branched) lateral axes, often congested into pseudowhorls, terminal or axillary; flowers bisexual, usually bilateral; sepals usually 5, connate, calyx radial to bilaterat, +/- tubular, bell-shaped, or wheel-shaped, persistent, occasionally enlarged in fruit; petals usually 5, connate, usually 2-lipped, lobes imbricate; stamens 4, didynamous to +/- equal, sometimes reduced to 2; filaments adnate to corolla; pollen grains tricolpate or hexacolpate; carpels 2, connate; ovary superior, unlobed to deeply 4-loped, 2-locular but appearing 4-locular due to development of false septa, with axile placentation; style usually apically divided, terminal to gymnobasic; stigmas 2, tiny and inconspicous at apices of style branches; ovules 2 per carpel, each laterally attached (attached on false septa very near the inrolled carpel margins), with one integument and a thin-walled megasporangium; nectar disk often present
Leaf characters
usually opposite, occasionaly whorled, simple, sometimes lobed or dissected, or pinnately or palmately compound, entire to serrate
Stipules
absent
Fruit characters
a drube with 1-4 pits, an dehiscent, 4-seeded pod, or schizocarp splitting into 4 nutlets or 4 drupelets; endosperm scanty or lacking
Hairs
Present, glandheaded, with ethereal oils (including terpenoids), and simple
