Goldenrod, Upland White - Solidago ptarmicoides

Solidago ptarmicoides, also known as Oligoneuron album, Prairie Goldenrod, Stiff Aster, White Flat-top Goldenrod, Sneezewort Goldenrod, Upland White Aster, or Upland White Goldenrod, is a perennial wildflower native to Michigan and the Upper Peninsula. The plethora of names reflect this plant's unique appearance. Not quite an aster,  but quite unlike most goldenrods. The flowers are white and aster-sized, larger than the flowers of typical goldenrods. Originally classified as an aster, this plant is noted in Michigan Flora as hybridizing naturally with other goldenrods, especially on Drummond Island and along the Escanaba River. This it is now considered a goldenrod, but the goldenrod family is also being reevaluated, so more name changes may be in the future. 
 
Whatever you call it, this is a pretty plant. The leaves are long and more prominent near the base. Flower stalks have numerous white flowers with long petals in late summer. Like many plants adapted to harsh shoreline or rock face environments where competition is not a major concern, it is naturally short, typically 1 to 2 feet. If conditions allow, it will form a low mound with striking white flowers over dark green foliage. In more barren locations, it may appear as a few leafy stalks with large flower clusters above.
 
It prefers gravel, sand, or rocky conditions and is a resident of jack pine plains and other sandy areas; riverbanks but also fens and dry prairies; calcareous soils along Lake Huron; and rock outcrops, crevices, and ledges on Lake Superior. Full sun (more than 6 hours at peak summer) is best, but light shade is tolerated. This plant will tolerate garden loams as long as they are well-drained.
 
Popular with butterflies and other pollinators. Seeds are eaten by goldfinches and others in fall. Drought tolerant.
 
Sources:
Michigan Flora
Missouri Botanical Garden Plant Finder
Minnesota Wildflowers
iNaturalist
Illinois Wildflowers