Geographic distribution of sites occupied by Crataegus sect. Douglasianae and C. sect. Salignae

Geographic distribution of sites occupied by Crataegus sect. Douglasianae and C. sect. Salignae samples, together with those occupied by the C. subg. Americanae taxa with which comparison is made in Dickinson et al. (2021; Fig. 9 and Supplementary Table S1). These sites are plotted on the map of the Köppen-Geiger climate classification (Kottek et al. 2006; Rubel et al. 2017; see http://koeppen-geiger.vu-wien.ac.at/present.htm) and visualized using Google Earth Pro. Conversion of the voucher specimen data in Table S1 to the Google Earth Keyhole Markup Language (.kml) was carried out using the EarthPoint exceltokml function (https://www.earthpoint.us/exceltokml.aspx; Clark undated). Most voucher specimens are held in the Green Plant Herbarium (TRT) of the Royal Ontario Museum, but additional voucher data were obtained from specimens on loan from, or online data provided by, other herbaria identified by their Index Herbariorum acronym. Clark, W. Undated. Earthpoint—Tools for Google Earth. Available online: http://www.earthpoint.us/ (accessed on various dates 2015-2021). Dickinson, T.A.; Yan, B.X.; Han, S.; Zarrei, M. Niche Shifts, Hybridization, Polyploidy and GeographicParthenogenesis in Western North American Hawthorns (Crataegus subg. Sanguineae, Rosaceae). Agronomy 2021, 11, 2133, doi:https://doi.org/10.3390/agronomy11112133. Kottek, M.; Grieser Jr Beck, C.; Rudolf, B.; Rubel, F. World Map of the Köppen-Geiger Climate Classification Updated. Meteorol. Z. 2006, 15, 259–263, doi:10.1127/0941-2948/2006/0130. Rubel, F.; Brugger, K.; Haslinger, K.; Auer, I. The Climate of the European Alps: Shift of Very High Resolution Köppen-Geiger Climate Zones 1800–2100. Meteorol. Z. 2017, 26, 115–125, doi:10.1127/metz/2016/0816.