. . . . . . . . . "Papilio glaucus" . . "Centaurea americana" . . "Richard Barnes. 2016. Papilio glaucus nectar plant Centaurea americana. iNaturalist.org. Accessed at <https://www.inaturalist.org/observations/3344010> 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." .