Common name(s): Cowbane
- Wikipedia. Online encyclopedia entry (if defined).
- Google images. Web search for photographs.
- GRIN. Taxonomical details, with common names, distribution, and synonyms.
- The Plant List. Taxonomical lookup
Links for Oxypolis rigidior
- Dave's Garden PlantFiles - Profile page with horticultural basics, and member-contributed photos and comments.
- Illinois Wildflowers - Informative illustrated page with description and cultivation details, also covering range and faunal associations. (2 photos)
- Lady Bird Johnson Wildflower Center - Plant description and characteristics with notes on distribution, culture, and propagation. (6 photos)
- Missouri Plants - Description and photographs of botanical features, with notes about habitat and native status. (7 photos)