Annual or parennial herbs, rarely shrubs, usually glabrous and bitter. Leaves opposite, rarely alternate or whorled, nearly always simple and entire; stipules wanting. Flowers regular, hermaphrodite, solitary or cymose. Calyx inferior, 4–5-lobed or -partite, lobes imbricate. Corolla gamopetalous, hypogynous, 4–5-.lobed or -partite, lobes twisted to the right (valvate in Liparophyllum). Stamens 4–5, inserted on the throat or tube of the corolla and alternate with its lobes; filaments filiform or dilated at the base; anthers 2-celled, introrse. Ovary superior, 1-celled, or 2-celled by the meeting of 2 intruded parietal placentas; style single, short or long; stigma entire or 2-lobed or 2-lamellate; ovules numerous in each cell. Fruit a 1- or 2-celled capsule with septicidal dehiscence, rarely fleshy or indehiscent. Seeds numerous, small; albumen copious, fleshy; embryo minute.

A large and very natural order, found nearly all over the world, but most abundant in the mountainous regions of the Northern Hemisphere. Genera about 50; species estimated at 500, almost without exception possessing bitter and tonic properties. The yellow gentian (Gentiana lutea) produces gentian-root, one of the earliest-known medicines, and still frequently used. Other species of Gentiana and of the allied genera Erythrea, Chlora, Frasera, Sabbatia, &c, have very similar qualities. Of the 3 genera found in New Zealand, Gentiana has the range of the whole order; Sebæa occurs in Australia, eastern Asia, and South Africa; while Liparophyllum is confined to Tasmania and New Zealand.

* Leaves opposite. Corolla-lobes contorted in bud.

Flowers small. Corolla cylindric; lobes spreading. Ovary 2-celled. Style deciduous	1. SebyÆa.
Flowers large. Corolla campanulate or rotate. Ovary 1-celled. Style persistent	2. Gentiana.

** Leaves alternate or tufted. Corolla-lobes induplicate-valvate.

Small herb with linear tufted leaves. Fruit fleshy

3. Liparophyllum.