Crataegus subg. Americanae El Gazzar sect. Coccineae Loudon ser. Rotundifoleae (Egglest. ex Egglest.) Rehder; Crataegus chrysocarpa individuals shown to be tetraploid by flow cytometry (Talent & Dickinson 2005).
Project 2423: T. A. Dickinson, B. X. Yan, S. Han, M. Zarrei. 2021. Niche Shifts, Hybridization, Polyploidy and Geographic Parthenogenesis in Western North American Hawthorns (Crataegus subg. Sanguineae, Rosaceae). Agronomy. 11 (11):2133.
Viewing Folio F1030 Crataegus chrysocarpa Ashe (tetraploid) containing 10 media.