Why is the ninth month called September?
late 14c., genciane, from Old French genciane and directly from Latin gentiana, said by Pliny to be named for Gentius, king of ancient Illyria who discovered its properties. This likely is a folk-etymology, but the word may be Illyrian nonetheless, because the suffix -an frequently occurs in Illyrian words.
(genus Gentiana), any of about 400 species of annual or perennial (rarely biennial) flowering plants of the family Gentianaceae distributed worldwide in temperate and alpine regions, especially in Europe and Asia, North and South America, and New Zealand. They are especially a notable feature of mountain regions, where the moisture-loving plants have access to underground water in summer and snow cover in winter. Gentian flowers are typically blue (hence "gentian blue") or purplish blue but may be purple, violet, mauve, yellow, white, or even red; the four or five petals are usually united into a trumpet, funnel, or bell shape. The flowers have been used in the making of dyes, especially Gentiana pneumonanthe, a source of blue dye. The tough fibrous roots were once used herbally for putative alimentary cures, and the name gentian derives from Gentius, king of ancient Illyria and alleged discoverer of the plant's medicinal value. Gentiana lutea, the yellow gentian, is found in Europe and western Asia and is the source of a flavouring in liqueurs.