. . . . . . . . . "Bombus vagans bolsteri" . . "Centaurea nigra" . . "Don Sutherland. 2015. Bombus vagans bolsteri nectar plant Centaurea nigra. iNaturalist.org. Accessed at <https://www.inaturalist.org/observations/6548990> 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." .