GRIN. Taxonomical details, with common names, distribution, and synonyms.
Links for Echinacea paradoxa
Dave's Garden PlantFiles - Profile page with horticultural basics, and member-contributed photos and comments. (zones 3a-9b) (11 photos)
Kemper Center - Plantfinder page for one of the plants growing at the Missouri Botanical Garden, with usually one or more photos, horticultural information, and noteworthy characteristics. (zone 5 to 8) (2 photos)
Missouri Plants - Description and photographs of botanical features, with notes about habitat and native status. (6 photos)