Xylorhiza cognata is a rare species of flowering plant in the aster family known by the common names Mecca-aster and Mecca woodyaster. It is endemic to Riverside County, California, where it is known only from the Mecca Hills and Indio Hills of the Sonoran Desert. It grows in scrubby habitat in dry desert canyons. It is a shrub with branching stems that may approach 1. 5 meters in length. They are hairy and glandular when new and lose their hairs with age. The leaves are lance-shaped to oval with smooth, toothed, or spiny edges. The inflorescence is a solitary flower head with up to 30 or more lavender or pale blue ray florets, each of which may measure over 2 centimeters in length. Flowering begins in January. The fruit is an achene which may be over a centimeter long, including its pappus of bristles. Threats to this species include vehicles in its habitat.