Fl. 82 mm wide; perianth segments broadly ovate, blunt, truncate, pale greenish yellow, with a slight, pale mucro, spreading, plane to a little concave, with broad midrib showing, smooth and of heavy substance, overlapping half or more; the inner segments more narrowly ovate, shouldered at base, with margins wavy; corona bowl-shaped, lightly ribbed and frilled, vivid yellow, with a narrow band of orange at rim, rim notched and dentate.

Named for sand dunes on Lake Superior shoreline; fishing village of same name in Upper Michigan.