Lewisia longipetala is a rare species of flowering plant in the purslane family known by the common names long-petalled lewisia and Truckee lewisia. It is endemic to the Sierra Nevada of California, where it is known from less than 20 locations in areas not far from Lake Tahoe. It grows in subalpine and alpine climates in moist areas in rocky habitat, such as talus that retains patches of snow year-round. Most specimens grow on north-facing slopes with little surrounding vegetation. The plant thrives in the snow, growing largest and most densely in areas of high snowpack and becoming easily water-stressed when far away from areas with snow.