Flat-top Goldenrod Posted on July 28, 2012 by Axie Reply Growing at water’s edge at Longfellow and at the Needham Town Forest. Blooms late summer through fall. Aster Family. Native. Flat-top Goldenrod, Grass-leaved Goldenrod (Euthamia graminifolia) Share this:Click to email a link to a friend (Opens in new window)Click to share on Facebook (Opens in new window)Click to print (Opens in new window)Click to share on Pinterest (Opens in new window)