. . . . . . . . . "Epargyreus clarus" . . "Silphium" . . "D. Tilson. 2015. Epargyreus clarus nectar plant Silphium. iNaturalist.org. Accessed at <https://www.inaturalist.org/observations/6922523> on 05 Apr 2018." . . . . "http://iNaturalist.org is a place where you can record what you see in nature, meet other nature lovers, and learn about the natural world." .