References

For Ratibida

Cronquist, A. 1980. Asteraceae, Volume I, Vascular flora of the Southeastern United States. University of North Carolina Press, Chapel Hill, N.C. Google Scholar

Richards, E.L. 1968. A monograph of the genus Ratibida. Rhodora 70: 348-393. Google Scholar

Urbatsch, L.E., and P.B. Cox. 2006b. Ratibida. In Flora of North America Editorial Committee. 2006c. Flora of North America north of Mexico. Volume 21, Magnoliophyta: Asteridae, part 6: Asteraceae, part 3. Oxford Univ. Press, New York, NY. 616 pp. Google Scholar