Many other camellias are grown as ornamental plants for their flowers ; about 3,000 cultivars and hybrids have been selected , many with double flowers , as in the gallery below . Camellia japonica ( often simply called Camellia ) is the most prominent species in cultivation , with over 2,000 named cultivars ; next are C. reticulata , with over 400 named cultivars , and C. sasanqua , with over 300 named cultivars . Among the ornamental species , the Japanese Camellia ( C. japonica ) ( which despite its name is also found in Korea and Eastern China ) and C. sasanqua are perhaps the most widely known , though most camellias grown for their flowers are cultivars or hybrids .