Trees, shrubs, or herbs, rarely climbing. Leaves opposite or whorled, simple, entire or very rarely toothed or lobed. Stipules always present, usually interpetiolar, either free or united with the petioles into a sheath, or connate into a sheath or ring surrounding the stem within the petioles; in the tribe Galiæ resembling the leaves, and with them forming a whorl round the branch. Flowers regular, hermaphrodite or unisexual, variously arranged. Calyx-tube adnate to the ovary; limb 4–5-toothed or cupular, sometimes wanting. Corolla gamopetalous, tubular, funnel - shaped, campanulate, or rotate, usually 4–5-lobed; lobes valvate or imbricate or contorted. Stamens inserted on the tube or mouth of the corolla, equal in number to its lobes. Ovary inferior, 2-many-celled, crowned by a fleshy disc; styles 1 or 2 or more; ovules solitary or 2 or more in each cell. Fruit very various, a drupe or berry or capsule, or composed of dehiscent or indehiscent cocci. Seeds with fleshy or horny albumen; embryo straight or curved; radicle superior or inferior.

One of the largest and best-defined orders in the vegetable kingdom, containing more than 350 genera and 4000 species. With the exception of the tribe Galieæ, which is almost entirely temperate, the species are mainly tropical or subtropical, and are especially plentiful in the warmer portions of South America. The medicinal properties of the order are most important. Out of many excellent drugs yielded by it, quinine and ipecacuanha are the best known and the most valuable. Among the species used for food the most noteworthy is the coffee-plant, which is now cultivated in all warm countries, and is of immense commercial importance. Many ornamental plants belong to the order, the various kinds of Bouvardia, Gardenia, Ixora, &c, being well-known examples. Of the 4 New Zealand genera, Coprosma extends to Australia and Tasmania, the Pacific Islands, New Guinea, and the mountains of Borneo. Nertera has the same distribution, and is found in South America as well. The two remaining genera are widely distributed in the north temperate zone.