. . . . . . . . . "Colias eurytheme" . . "Helminthotheca echioides" . . "Coty Sifuentes-Winter. 2016. Colias eurytheme nectar plant Helminthotheca echioides. iNaturalist.org. Accessed at <https://www.inaturalist.org/observations/4218766> 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." .