Reference citation:
Scott, J.A. (2007). Lepidoptera of North America 13. Flower Visitation by Colorado Butterflies (40,615 Records) with a Review of the Literature on Pollination of Colorado Plants and Butterfly Attraction (Lepidoptera: Hesperioidea and Papilionoidea). Lepidoptera of North America

Source citation:
National Database Plant Pollinators. Center for Plant Conservation at San Diego Zoo Global. Accessed via https://saveplants.org/national-collection/pollinator-search/ on 2020-06-05.

Source archive URL:
https://github.com/globalbioticinteractions/cpc-pollinators/archive/c0ea6f2fd5d7bc9d2db5cb0f27248b84637e20ef.zip

Reference citation:
Even Dankowicz. 2013. Colias eurytheme nectar plant Cirsium arvense. iNaturalist.org. Accessed at on 23 Jan 2021.

Source citation:
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.

Source archive URL:
https://github.com/globalbioticinteractions/inaturalist/archive/8d3e240982f0f68b3da2767abe9b27e5bbfeed41.zip

Reference citation:
Chuck Sexton. 2016. Colias eurytheme nectar plant Cirsium arvense. iNaturalist.org. Accessed at on 23 Jan 2021.

Source citation:
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.

Source archive URL:
https://github.com/globalbioticinteractions/inaturalist/archive/8d3e240982f0f68b3da2767abe9b27e5bbfeed41.zip