References

For Rugelia

Barkley, T.M. 1999. The segregates of Senecio, s.l., and Cacalia, s.l., in the flora of North America north of Mexico. Sida 18: 661-672. Google Scholar

Barkley, T.M. 2006h. Rugelia. In Flora of North America Editorial Committee. 2006b. Flora of North America north of Mexico. Volume 20, Magnoliophyta: Asteridae, part 6: Asteraceae, part 2. Oxford Univ. Press, New York, NY. 666 pp. Google Scholar

Bremer, K. 1994. Asteraceae: cladistics and classification. Timber Press, Portland, OR. 752 pp. Google Scholar

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

Pippen, R.W. 1978. Cacalia. N. Amer. Fl. II 10: 151-159. Google Scholar