There are 490 individual species in the genus. Hypericums vary from herbaceous annual or perennials 5-10 cm tall to shrubs and small trees up to 12 m tall. The leaves are opposite, simple oval, 1-8 cm long, either deciduous or evergreen. The flowers vary from pale to dark yellow, and from 0.5-6 cm in diameter, with five (rarely four) petals, most having prominent stamens. The fruit is usually a dry capsule which splits to release the numerous small seeds. Some species are used as ornamental plants and have large, showy flowers. Numerous hybrids and cultivars have been developed for use in horticulture, such as H. - moserianum (H. calycinum - H. patulum), H. 'Hidcote' and H. 'Rowallane'. All of the above cultivars have gained the Royal Horticultural Society's Award of Garden Merit.