During hot months, prairies come alive with phenomenal displays of wildflowers and the prairie restorations of the Rotary Centennial Arboretum at Riverside Park are, right now, in full bloom. There you can find this week’s wildflower: Prairie Fleabane (Erigeron strigosus). With flowerheads that look like small, delicate daisies, prairie fleabane is a member of Asteraceae, the asters. Asteraceae is one of the two biggest families of plants in the world along with Orchidaceae, the orchids. Which family is bigger depends on who’s counting what as a species.