Latin ex — out, agere — to drive, referring to the purgative properties of some species.

Herbs. Leaves opposite, simple, entire, stalkless except in e. affine. Flowers blue or white, solitary or in forked clusters. Calyx and corolla 4-5-lobed, the petal lobes spreading. Stamens short, enclosed. Fruit a 2-valved capsule.

Grown for the simple, attractive flowers.

Seed.

Leaves stalked in the cultivated species.

69 species from the Old World tropics.

Klackenberg (1985).

Source: Spencer, R. (2002). Gentianaceae. In: Spencer, R.. Horticultural Flora of South-eastern Australia. Volume 4. Flowering plants. Dicotyledons. Part 3. The identification of garden and cultivated plants. University of New South Wales Press.