SUN ROSE

also called Rock Rose, any of about 100 species of low-growing flowering plants making up the genus Helianthemum in the rock rose family (Cistaceae), the flowers of which resemble single roses. They include several sunny garden plants, varieties of which are useful in rock gardens and wild gardens. Helianthemum apenninum, H. cinereum, H. glaucum, and H. hirsutum are dwarf shrubby wildlings native to Europe. H. nummularium, also European, has many cultivated varieties with flowers ranging from white to yellow and pink. In North America H. canadense, also called frostweed, H. corymbosum, and H. rosmarinifolium are low eastern wildlings. H. scoparium, called rock, or sun, rose, is a rushlike shrub that grows to 30 cm (1 foot) in height (but with lower varieties) and is native to California. Also known as rock rose (q.v.) are related plants of the genus Cistus (family Cistaceae).