References
For Rhinotropis
Abbott, J.R. 2011. Notes on the disintegration of Polygala (Polygalaceae), with four new genera for the flora of North America. J. Bot. Res. Inst. Texas 5: 125-137. Google Scholar
Abbott, J.R. 2021. Polygalaceae. In Flora of North America Editorial Committee. 2021. Flora of North America north of Mexico. Volume 10, Magnoliophyta: Proteaceae to Elaeagnaceae. Oxford Univ. Press, New York, NY. 456 pp. Google Scholar
Wendt, T. 1979. Notes on the genus Polygala in the United States and Mexico. J. Arnold Arb. 60: 504-514. Google Scholar