A review of the chemistry of the genus Crataegus

► The chemistry of approximately 30 Crataegus species has been reported. ► The literature up to early 2011 is reviewed. ► The biological diversity of the genus Crataegus is outlined. ► The traditional use and ethnobotany of the genus Crataegus are briefly described. ► A high degree of phytochemical diversity was exhibited in the flavonoid profiles.