Bibliography for Aesculus hybrid identification in the American South
dePamphilis, C. W., & Wyatt, R. (1989). Hybridization and introgression in buckeyes (aesculus: hippocastanaceae): a review of the evidence and a hypothesis to explain long-distance gene flow. Systematic Botany, 593–611. https://doi.org/10.2307/2419005
"Directional migration and arrival of hummingbirds after peak flowering would enforce a directional pattern of gene flow and could generate an asymmetrical hybrid zone of unusually great width."
Online at:
http://amborella.huck.psu.edu/pdf/dePamphilis_Wyatt_SysBot_1989.pdf
Hardin, James W. (1957) “Studies in the Hippocastanaceae, IV: hybridization in aesculus. Rhodora, vol. 59, no. 704, pp. 185–203. JSTOR, http://www.jstor.org/stable/23306282.
First treatment of the hybrid Aesculus of North America. Has a map of the various regions where hybridization occurs. Has subsections describing each hybrid. Has excellent charts that visualize the intermediate nature of distinguishing characteristics.
Related observations:
https://www.inaturalist.org/observations/40332786
https://www.inaturalist.org/observations/80691768
https://www.inaturalist.org/observations/113974575
https://www.inaturalist.org/observations/150458533
https://www.inaturalist.org/observations/204649810
