Claytonia is a genus of succulent, low-growing perennials that belong to the purslane family, Portulacaceae. The genus is best known for the small wildflowers that these plants produce from the early to mid spring. Most the 20 recognized species of Claytonia are native to North America, but less common species have also been discovered in South America, New Zealand and Asia. Claytonias are considered to be very difficult to cultivate outside of their natural setting unless a gardener has access to a special type of greenhouse.
Plant species of the Claytonia genus have long, thick roots and tubers that produce new hairless, fleshy foliage from the early spring through the late summer. Most species produce stems full of multiple, simple flowers that blossom in the spring with five individual petals and five sepals. These flowers are cup-shaped or bowl-shaped and are usually colored yellow or white.
The Claytonia species spring beauty, C. virginica, is a particular favorite amongst wildflower enthusiasts. Spring beauty is a small perennial that grows in clumps from darkly colored tubers. The plant produces fleshy leaves that are broad when they emerge from the earth and then narrow to become as thin as grass. In the spring, a flower stem that is 3 to 12 inches (about 7 to 30 centimeters) long grows above the foliage and blossoms with a series of up to six white flowers with pink veins.
Despite the reputation that Claytonias have of being difficult to cultivate outside of the wild, advanced rock gardeners are sometimes able to raise healthy specimens in controlled environments. The more common Claytonias grow in rocky or gritty soil in temperate regions that have a particularly cool spring. As a result, most members of the Claytonia genus will only prosper outside of the wild in a type of habitat known as an alpine greenhouse.
An alpine greenhouse is a type of greenhouse that is designed to mimic the natural climate of plants like members of the Claytonia genus. Instead of providing additional heat and humidity like a traditional greenhouse, alpine greenhouses provide shade and temperature control that create similar conditions to the alpine environment. In the case of the Claytonia genus, these greenhouses mimic the all-important cool summers that these types of plants need in order to survive.
Claytonias can be propagated from seed during the early spring in an alpine greenhouse with minimal effort. These plants require very fertile but well-drained soil that will need to be kept moist throughout the growing season. Most species of Claytonia require some degree of direct sunlight.