. . . . . . . . . "Colias croceus" . . "Centaurea calcitrapa" . . "Jakob Fahr. 2016. Colias croceus nectar plant Centaurea calcitrapa. iNaturalist.org. Accessed at <https://www.inaturalist.org/observations/4969497> 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." .