Flat-topped White Aster

Doellingeria umbellata

Description from Minnesota Wildflowers

Flowers are in flat clusters to 10 inches across. Individual flowers are from ½ to ¾ inches across with 2 to 15 irregularly spaced white petals (ray flowers) and a yellow center that turns gray-purple with age. Occasionally the cluster is dome shaped instead of flat.

Leaves are 3 to 6 inches long and to 1 inch wide, tapering to a point at both ends, with little or no leaf stem. The edges are rough, but toothless. Attachment is alternate. The main stem is sometimes purple.