Gentiana andrewsii 
Bottle gentian is a blue-flowered woodland garden plant that grows to 1-2 feet in height.
 
Unlike most flowers the blossoms of the bottle gentian stay closed at the tip, looking almost like an old-fashioned Christmas light.
 
These beauties thrive in moist soils and cool shade, and typically do not flower until the Fall, serving as a later food source for bumblebees.