Lewisia is a genus of western North America species in the Portulacaceae family. They usually have a rosette of fleshy leaves that resemble a succulent, and may be produced from a thickened taproot or tuber. Some species pass the long arid season by becoming dormant. Two good books on this subject are Davidson, 2000 and Mathew, 1989. More information on them is found in References. Common species like Lewisia tweedyi and Lewisia cotyledon are evergreen so not included here.
Lewisia pygmaea is one of the smaller members of this genus and has tufted leaves instead of a rosette. It has a short compact, carrot-like or branched rootstock. It is widespread from Alaska to California and east to Montana and New Mexico where it is found in open places in the mountains. It prefers seasonally moist sites. Leaves appear in spring and flowering can continue until frost. Flower color ranges from white to pink to purple. Matthew suggests these plants should be kept just moist throughout the year and not be over-potted. Photos by Mary Sue Ittner.
Lewisia rediviva is the state flower of Montana, USA, but it is widely distributed throughout the western United States. The common characteristic of the habitats where it is found is a dry summer climate without heavy rainfall, and a long cool or cold winter growing season. In the coldest areas it sprouts in fall, waits under the snow, and blooms in spring. In milder climates it grows in winter and blooms in spring. In all cases, it does not appreciate summer water. It has a short thick caudex that can be single or develop into multiple crowns. Flowers are white or pink, and vaguely resemble cactus flowers (but without the spines). The plants are summer dormant and bloom nicely in spring once established. It is known as bitterroot because the root was a food source for western North American Indians. The plant was first brought to the attention of science when it was collected during the Lewis & Clark expedition, and the genus is named after Meriwether Lewis, who tried eating the roots of Lewisia rediviva: "I...found that they became perfectly soft by boiling, but had a very bitter taste, which was naucious to my pallate, and I transfered them to the Indians who had ate them heartily." Seeds germinate readily in autumn after 20 days post sowing. The third photo shows two week old seedlings. First three photos by Nhu Nguyen, fourth by Michael Mace. Cultural information on L. rediviva can be found here, there is a large collection of photos here, and more information on the history of the plant here.
