Clouded Sulphurs nectar at flowers such as Milkweed (Asclepias sp.), Butterfly Bush (Buddleja sp.), Coneflower (Dracopis, Echinacea, and Rudbeckia), Alfalfa (Medicago sativa), Dandelion (Taraxacum sp.), Clover (Trifolium sp.), and Tall verbena (Verbena bonariensis) and many more.
Echinacea angustifolia was widely used by the North American Plains Indians for its general medicinal qualities.
One particular forb, the purple coneflower, is recognized more readily by its scientific name Echinacea purpurea, or just Echinacea, which is used as an herbal remedy for colds.