. . . . . . . . . "Bombus griseocollis" . . "Asclepias tuberosa" . . "Adam Ray Weaver. 2017. Bombus griseocollis nectar plant Asclepias tuberosa. iNaturalist.org. Accessed at <https://www.inaturalist.org/observations/6875676> 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." .