References
For Sorbus
Aldasoro, J.J., C. Aedo, F.M. Garmendia, F. Pando de la Hoz, and C. Navarro. 2004. Revision of Sorbus subgenera Aria and Torminaria (Rosaceae-Maloideae). Systematic Botany Monographs 69: 1-148. Google Scholar
Jones, G.N. 1939. A synopsis of the North American species of Sorbus. J. Arnold Arb. 20: 1-43. Google Scholar
Kalkman. 2004. In Kubitzki, K., ed. 2004. The families and genera of vascular plants. VI. Flowering plants – Dicotyledons – Celastrales, Oxalidales, Rosales, Cornales, Ericales. Springer, Berlin. 489 pp. Google Scholar
McAllister, H. 2005. The genus Sorbus: mountain ash and other rowans. Royal Botanic gardens, Kew. 252 pp. Google Scholar
Zika, P.F., and S.M. Bailleul. 2014. Sorbus. In Flora of North America Editorial Committee. 2014. Flora of North America north of Mexico. Volume 9, Magnoliophyta: Picramniaceae to Rosaceae. Oxford Univ. Press, New York, NY. 713 pp. Google Scholar