Tetradymia axillaris is a flowering plant in the Asteraceae (Sunflower) family known by the common names Cotton Catclaw and Longspine Horsebrush. This is a plant of the sagebrush and desert plant communities of the southwestern United States. In California it is found from Mono County southward to Riverside County. The plant forms a sprawling thicket and is very spiny. The spine is a modified central leaf vein; the green leaves dry and their tissues fall away, leaving the veins as hard, sharp spines. When in foliage the bush has green, hairy stems and bears yellow rayless flowerheads in the axils, or angles, of the newest branches. The fruits are released in masses of cottony seed. The sharp spines were used as tattooing needles by the Kawaiisu Native Americans. This plant should be used away from traffic where the spines will not be a problem. This is a very different plant from Catclaw Acacia (Senegalia greggii) which is a legume that grows in the desert further south.