For Astraea
Berry, P.E., and B.W. van Ee. 2016. Astraea. In Flora of North America Editorial Committee. 2016. Flora of North America north of Mexico. Volume 12, Magnoliophyta: Vitaceae to Garryaceae. Oxford Univ. Press, New York, NY. 603 pp. Google Scholar
Silva, O.L.M. da, and I. Cordeiro. 2020. A taxonomic revision of Astraea (Euphorbiaceae). Plant Syst. Evol. 306:41. https://doi.org/10.1007/s00606-020-01661-z Google Scholar