References
For Catharanthus
Endress, M.E., U. Meve, D.J. Middleton, and S. Liede-Schumann. 2018. Apocynaceae. In Kadereit, J., & V. Bittrich. 2018. The families and genera of flowering plants. XV. Flowering plants. Eudicots. Apiales, Gentianales (except Rubiaceae). Springer, Cham. Google Scholar
Lemke, D.E. 2023d. Catharanthus. In Flora of North America Editorial Committee. 2023c. Flora of North America north of Mexico. Volume 14, Magnoliophyta: Gentianaceae to Hydroleaceae. Oxford Univ. Press, New York, NY. 505 pp. Google Scholar
Snoeijer, W. 1996. Catharanthus roseus, the Madagascar Periwinkle, a review of its cultivars. Wageningen Agricultural University Papers 96-3: 47-120. Google Scholar
van Bergen, M.A. 1996. Revision of Catharanthus G. Don; series of revisions of Apocynaceae XLI. Wageningen Agricultural University Papers 96-3: 1-46. Google Scholar