Lewisia brachycalyx is a species of flowering plant in the purslane family known by the common name shortsepal lewisia. It is native to the mountains of the southwestern United States and Baja California, where it grows in moist habitat such as meadows. It is a perennial herb growing from a short thick taproot and caudex unit. It produces a basal rosette of thick, fleshy, blunt-tipped narrow leaves up to 8 centimeters long. The inflorescence is under 4 centimeters tall, taking the form of a cluster of several flowers sitting atop the leaf rosette. Each flower has 5 to 9 shiny white or pink petals about 2 centimeters long. At the center are many stamens and stigmas clumped together.