Gentiana
Gentiana is a genus of flowering plants belonging to the gentian family (Gentianaceae), the tribe Gentianeae, and the monophyletic subtribe Gentianinae. With about 400 species it is considered a large genus. They are notable for their mostly large, trumpet-shaped flowers, which are often of an intense blue. The genus name is a tribute to Gentius, an Illyrian king who may have been the discoverer of tonic properties in gentians. Habitat. This is a cosmopolitan genus, occurring in alpine habitats in temperate regions of Asia, Europe and the Americas. Some species also occur in northwestern Africa, eastern Australia, and  New Zealand. They are annual, biennial, and perennial plants. Some are evergreen, others are not. Many gentians are difficult to grow outside their wild habitat, but several species are available in cultivation. Gentians are fully hardy and can grow in full sun or partial shade. They grow in well-drained, neutral-to-acid soils rich in humus. They are popular in rock gardens. Uses. Many beverages are made with gentian root. "Gentiana lutea" is used to produce "gentian", a distilled beverage produced in the Alps and in the Auvergne. Some species are harvested for the manufacture of apéritifs, liqueurs, and  tonics. Gentian root is a common beverage flavouring for bitters. The soft drink Moxie contains gentian root. The French apéritif Suze is made with gentian. Americano apéritifs contain gentian root for bitter flavoring. It is an ingredient in the Italian liqueur Aperol. It is also used as the main flavor in the German after-dinner digestif called Underberg, and the main ingredient in Angostura bitters and Peychaud's Bitters. The bitter principle of gentian root is primarily gentiopicrin (also called gentiopicroside), a glycoside. A 2007 paper by a Japanese group identified 23 compounds in fresh gentian root. Gentiopicrin was absent  from fresh root, so it possibly develops during drying and storage of the root. Gentian has had a limited use in perfumery, most notably as a glycerine soap (Crabtree & Evelyn) and a perfume (Corday's Possession, 1937). Pharmacological uses. Great yellow gentian ("Gentiana lutea") is used in herbal medicine for digestive problems, fever, hypertension, muscle spasms, parasitic worms, wounds, cancer, sinusitis, and malaria, although studies have shown minimal efficacy beyond that of a placebo with regard to the treatment of anxiety and ADHD in children. It has been studied and proven in effectively managing dyspepsia. "Gentiana punctata" leaves and roots  have been used in traditional Austrian medicine internally and externally as liqueur or tea for disorders of the gastrointestinal tract, skin, locomotor system, liver and bile, and for pediatric problems, fever, flu, rheumatism, and gout. "Gentiana purpurea", "Gentiana punctata", and "Gentiana pannonica" are used to produce bitter schnapps, traditionally used as a digestive aid. In Ayurvedic medicine the endangered Indian gentian "Gentiana kurroo" has been used as a medical herb, but has been replaced with the Himalayan plant "Picrorhiza kurroa", Plantaginaceae or "Picrorhiza scrophulariiflora" (胡黃蓮 Hú Huáng Lián) from traditional Chinese medicine. Symbolism. The gentian flower was used as the  emblem of the Minamoto clan, one of the four great clans that dominated Japanese politics during the Heian period and went on to establish the first Shogunate in the aftermath of the Genpei War. It is the official flower of the German-speaking community of Belgium. Species. General. Gentians have oppositely arranged leaves, sometimes in a basal rosette. The trumpet-shaped flowers are usually deep blue or azure, but can be white, cream, yellow, or red. Many species are polymorphic with respect to flower color, bearing flowers of different colors. Blue-flowered species predominate in the Northern Hemisphere, with red -flowered species dominant in the Andes, where bird pollination is probably more often favored by natural selection. White-flowered species are scattered throughout the range of the genus but dominate in New Zealand. Most flowers are pentamerous, with five lobes in the corolla and five sepals. A few species have four to seven flower parts. The corolla has folds called plicae between the lobes. The style is short or absent. The ovary is mostly sessile and has nectary glands. Cultivation. Several gentian species may be found in cultivation, and are valued for the unusual intensity of their blue flowers. They  have a reputation for being difficult to grow. All require similar conditions – moist, rich, free-draining soil with an acid to neutral pH. They include: In addition, the following cultivars, of mixed or uncertain parentage, have gained the Royal Horticultural Society’s Award of Garden Merit: