The genus Aesculus ( /ˈɛskjʊləs/ or /ˈaɪskjʊləs/) comprises 13-19 species of woody trees and shrubs native to the temperate northern hemisphere, with 6 species native to North America and 7-13 species native to Eurasia; there are also several hybrids. Species are deciduous or evergreen. This genus has traditionally been treated in the ditypic family Hippocastanaceae along with Billia, but recent phylogenetic analysis of morphological and molecular data has led to this family, along with the Aceraceae (Maples and Dipteronia), being included in the soapberry family (Sapindaceae).