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. popular hybrids include "c. × hiemalis" ("c. japonica" × "c. sasanqua") and "c. × williamsii" ("c. japonica" × "c. salouenensis"). they are highly valued in japan and elsewhere for their very early flowering, often among the first flowers to appear in the late winter. late frosts can damage the flowers.