Heuchera ( or ) is a genus of largely evergreen perennial plants in the family Saxifragaceae, all native to North America. Common names include alumroot and coral bells. Description Heuchera have palmately lobed leaves on long petioles, and a thick, woody rootstock. The genus was named after Johann Heinrich von Heucher (1677–1746), an 18th-century German physician, and Professor at Wittenberg University. There are approximately 37 species, but the taxonomy of the genus is difficult because the species often intergrade with one another, hybridization is common, and the flowers change markedly in proportion as they develop. Distribution and habitat Alumroot species grow in varied habitats, so some species look quite different from one another, and have varying preferences regarding temperature, soil, and other natural factors. H. maxima is found on the Channel Islands of California, where it grows on rocky, windy, saline-washed ocean shores, and H. sanguinea, called coral bells because of its cerise flowers, can be found in the warm, dry canyons of Mexico and adjacent New Mexico and Arizona. In the Mid-Atlantic region of the United States, the plants grow best in shade. Several alumroots and their crosses are used as ornamental plants. Uses Native American peoples used some Heuchera species medicinally. The Tlingit used H. glabra as an herbal remedy for inflammation of the testicles caused by syphilis. To the Navajo, H. novamexicana was a panacea and a pain reliever. The roots of H. cylindrica had a variety of medicinal uses among the Blackfoot, Flathead, Kutenai, Okanagan, Colville, and Shuswap. Cultivation The majority of Heuchera sold for gardens are hybrids of H. americana, such as 'Green Spice'. The original 'Purple Palace' discovered in a palace in England is believed to be a H. micrantha × H. villosa hybrid, which was then crossed with H. americana. Another group of hybrids are crosses of Heuchera with Tiarella treated under the name × Heucherella. Gardeners and horticulturists have developed a multitude of hybrids between various Heuchera species. There is an extensive array of blossom sizes, shapes, and colors, foliage types, and geographic tolerances. They are valued as foliage plants, producing rosettes of leaves in shades of green, pink and bronze, often variegated or textured; with long thyrses of white, green, pink or red flowers in spring. The following cultivars have gained the Royal Horticultural Society's Award of Garden Merit:- 'Blackberry Jam' 'Can-Can' 'Green Spice' 'Lime Marmalade' 'Magic Wand' 'Marmalade' 'Obsidian' 'Purple