James H. Schutte
Family
Portulacaceae
Botanical Name
Lewisia
Plant Common Name
Lewisia
General Description
Thoughts of Meriwether Lewis and his companion William Clark boldly exploring the unknown reaches of the burgeoning United States are brought to mind by the genus Lewisia. This group of about 16 species of North American plants is named in honor of Lewis and found mostly in western alpine and mountainous areas, including those of Canada and Mexico. The number of species has long been debated by some experts as they often produce natural hybrids.
All Lewisia are perennials and either deciduous or evergreen. Most are low-growing and form mounds or rosettes of foliage and have stout taproots. Often thought of as succulents, the leaves are actually more thick and leathery. They vary considerably in shape, size and arrangement.
Showy large flowers are produced by most Lewisia. Arrangement is species dependent. They generally are borne in branched or un-branched clusters but are sometimes single. The blooms are cup-shaped or flat with petals fused at the base. Flower colors include white, rose or red, pink or apricot. Flowering usually occurs in summer or fall. The fruits are capsules which split to expel many glossy dark brown or black seeds.
Lewisias are popular wildflowers for rock and scree gardens. Bitter root ( Lewisia rediviva) is the state wildflower of Montana and among the showiest. Sierra lewisia ( Lewisia glandulosa) is native to California and produces large white or pink flowers. The tiny Lewisia nevadensis is a nice choice for container culture and there are quite a few wonderful hybrids to choose from.
Hardiness and culture are species dependent, but most Lewisia species grow best in conditions similar to their native habitats. Most thrive in exposed conditions and poor soils with excellent drainage. They are true rock dwellers that are perfectly happy wedged in wall crevices or rocky outcrops. Most prefer growing conditions with low humidity and lots of air circulation. Topdress plants with gravel to help keep the rosettes from rotting. Alpine gardeners should certainly grow a few colorful Lewisia in their summer beds.
