Herbs or shrubs, rarely small trees. Leaves alternate, often in unequally placed pairs, but never truly opposite, entire or lobed or pinnate; stipules wanting. Flowers regular or occasionally slightly irregular, hermaphrodite, solitary or cymose; bracts wanting. Calyx inferior, persistent, 4–5-toothed or -lobed. Corolla gamopetalous, hypogynous, 4–5-toothed or -lobed, campanulate or funnel-shaped or rotate, often plicate. Stamens 4–5, inserted on the tube of the corolla and alternate with its lobes; anthers free or conniving, dehiscing lengthwise or by apical pores. Ovary superior, 2-celled, rarely incompletely 4-celled; style terminal, simple; stigma entire or 2-lobed; ovules numerous, amphitropous, on prominent peltate placentas attached to the middle of the septum. Fruit a berry or capsule, usually 2-celled, many-seeded. Seeds small, compressed or reniform; albumen copious; embryo terete, curved or almost spiral, radicle next the hilum.

A large and widely diffused family, most numerous in the tropics, but extending northwards and southwards into most temperate regions. Genera between 60 and 70; species variously estimated, probably considerably over 1000. The order must be considered a dangerous one, from the large number of species containing narcotic and poisonous principles, as the deadly nightshade, henbane, tobacco, stramonium, &c. A few species are simply tonic and bitter, while others are pungent and stimulant, as the various kinds of capsicums. But, notwithstanding the generally suspicious character of the order, it nevertheless furnishes one of the chief articles of vegetable food in the potato, and also includes the tomato, egg-plant, and cape gooseberry. Among garden plants the genera Petunia, Salpiglossis, Cestrum, and Datura are the most noteworthy. The sole New Zealand genus is almost cosmopolitan.