The gentian family has showy flowers shaped into a tube with petals that flatten out at right angles from the tube.  4 or 5 sepals sometimes united, 4 or 5 united petals, 4 or 5 stamens (the same number as the petals and alternates with them), and 1 ovary that protrudes.  Leaves are usually opposite, undivided, and on stout stems.