For Cosmos
Cronquist, A. 1980. Asteraceae, Volume I, Vascular flora of the Southeastern United States. University of North Carolina Press, Chapel Hill, N.C. Google Scholar
Kiger, R.W. 2006. Cosmos. 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
Sherff, E.E., and E.J. Alexander. 1955. Compositae – Heliantheae – Coreopsidinae. North American Flora, series II, part 2. New York Botanical Garden. Google Scholar