A plant genus in the family BERBERIDACEAE. The common names of Barberry or Oregon Grape are also used for MAHONIA. The similar-named Bayberry is the unrelated MYRICA. Oregon Grape was classified by Pursh as a Berberis but Nuttall claimed it is different enough to call it a new genus, MAHONIA. Botanists insist on this name while horticulturists stay with Mahonia. They are shrubs with yellow wood and usually three-branched spines at the base of leafstalks. Flowers are yellow, six-petaled and fruit is a berry with one to several seeds. Members contain BERBERINE.