Rosaceae, the rose family, is a medium-sized family of flowering plants, including 4,828 known species in 91 genera.. The name is derived from the type genus Rosa.Among the most species-rich genera are Alchemilla (270), Sorbus (260), Crataegus (260), Cotoneaster (260), Rubus (250), and Prunus (plums, cherries, peaches, apricots, and …