Bottle gentian has deep blue, bottle shaped flowers that are about 2-4 cm in length. The flowers are clustered near the top of the stem. The "closed" term comes from the fact that the flowers are not open at the mouth, making them appear a little like buds. But, if you look carefully, you will be able to see that the top edges of the petals are wrinkly because of small ridges.The leaves are whorled along the stem and are about 4 1/2 inches long.

Bottle gentian is a fall blooming forb native to tallgrass prairies. The deep blue, bottle shaped blooms can only be pollinated through buzz pollinations via bumble bees, hawkmoths, and hummingbirds. If you open one of the flowers, you will see that the floral parts are fused together inside.