Any one of a genus (Gentiana) of herbaceous plants with opposite leaves and a tubular four- or five-lobed corolla, usually blue, but sometimes white, yellow, or red
A gentian is a small plant with a blue or purple flower shaped like a bell which grows in mountain regions. a small plant with blue or purple flowers that grows in mountain areas (gentiana, perhaps from Gentius king of ancient Illyria, in Southern Europe, who is said to have discovered the use of the plant as a medicine)