Conoclinium coelestinum (L.) DC.
Eupatorium coelestinum L.
Mist-flower, Blue Mistflower, Blue Boneset
Blue mistflower is native to North America.
Identification: Plants are 18-36" (45-91 cm) in height. Leaves are roughly triangular (deltate), opposite, wrinkly, with blunt teeth (dentate or dentate-crenate), up to 3" (7.6 cm) × 2" (5 cm). Flowers appear in clusters that are almost flat-topped, and 1-3" (2.5-7.6 cm) around. The flowers are brushlike disc flowers—composed of 40-50 threadlike disc florets—that are blue or purple. Flowers are ¼-⅜" (6.3-9.5 mm) in size, appearing from July to October. Technically these are composite flowers, like other members of the enormous aster family, but this species lacks ray flowers.
Conoclinium coelestinum at Illinois Wildflowers
Conoclinium coelestinum on jeffpippen.com
Conoclinium coelestinum on Wildflowers of the United States
Conoclinium coelestinum on FLORIDATA
Conoclinium coelestinum at the Missouri Botanical Garden
Conoclinium coelestinum at the Lady Bird Johnson Wildflower Center
1Steve Christman at Floridata says others have described the unique color as clear blue, powder blue, azure blue, bluish-purple, reddish-purple, blue-pinkish, and pink-purplish. He prefers 'sky-blue pink.'
Conoclinium coelestinum description by Thomas H. Kent, last updated 27 Jun 2017.
Range: Zones 4-11: