References
For Helianthus
Cronquist, A. 1980. Asteraceae, Volume I, Vascular flora of the Southeastern United States. University of North Carolina Press, Chapel Hill, N.C. Google Scholar
Heiser, C.B., Jr., D.M. Smith, S.B. Clevenger, and W.C. Martin, Jr. 1969. The North American sunflowers (Helianthus). Mem. Torrey Bot. Club 22: 1-218. Google Scholar
Kelley, W.A. 2003. Calandrinia. In Flora of North America Editorial Committee. 2003b. Flora of North America north of Mexico. Volume 4, Magnoliophyta: Caryophyllidae, part 1. Oxford Univ. Press, New York, NY. 559 pp. Google Scholar
Schilling, E.E. 2006c. Helianthus. 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
Schilling, E.E., C.R. Linder, R.D. Noyes, and L.H. Rieseberg. 1998. Phylogenetic relationships in Helianthus (Asteraceae) based on nuclear ribosomal DNA internal transcribed spacer region sequence data. Syst. Bot. 23: 177-187. Google Scholar
Ungberg, E.A., J.W. Horn, D.B. Poindexter, K.A. Bradley, and A.S. Weakley. 2024. Helianthus waccamawensis (Asteraceae), a new species of sunflower endemic to the Cape Fear Arch region of North and South Carolina (U.S.A.). J. Bot Res. Inst. Texas 18(2) 271-291. Google Scholar