Family: Gentianaceae
Common Name: Gentian

Grown for their intense blue flowers, and for the medicinal properties of their bitter roots, these perennials are found growing naturally in temperate, arctic or high tropical regions, mostly in Europe and Asia, with the largest number in China. They look wonderful in rock­eries and borders.

Species

G. acaulis, stemless gentian, zone 3, an alpine species, growing to 10 cm (4 in), is prob­ably the most widely grown. It forms rosettes of glossy, green, narrow leaves and spring brings a mass of dark blue, tubular flowers, with green-spotted throats. Cultivar 'Alba' produces white flowers.

G. asclepiadea, willow gentian, zone 6, grows to 1 m (3 ft), with dark blue flowers. Var. alba has white flowers.

G. farreri, zone 5, is a prostrate plant with blue flowers, striped with white.

G. lutea, great yellow gentian, zone 5, is one of the largest of the species, growing up to 2 m (6 ft), and uncommonly produces pale yellow flowers. It prefers damp conditions and is the major source of gentian root.

G. makinoi, zone 6, from Japan, grows to about 60 cm (2 ft). The bell-shaped, pale blue flowers are spotted.

G. saxosa, zone 8, from New Zealand, is a prostrate plant, to 15 cm (6 in), with loose rosettes of leaves and white, lobed flowers with brownish veins.

G. septem­fida, crested gentian, zone 3, grows to 20 cm (8 in), with bright blue flowers.

G. sino-ornata, zone 6, is a prostrate species, forming rosettes of leaves from which protrude deep blue flowers, paler at the base. It grows to 18 cm (7 in).

Cultivation

The seed of gentians must be sown fresh or it may take a year to germinate. Seed sown in spring of the previous year must be kept moist if it has not come up. Most species require well-drained, gritty soil, with added leaf mould or peat, although they sometimes have special requirements like most alpine plants. Most need a sunny position with plenty of summer moisture but should be kept dry in winter. All species need to be firmly anchored in the soil to avoid wind damage. Propagate species from seed, or divide root offsets in spring.

Climate

There are species suited to various cli­matic zones.