About Tetradymia axillaris A.Nelson
Tetradymia axillaris A.Nelson is a flowering plant in the daisy family, commonly known as longspine horsebrush and cottonthorn. It is native to the sagebrush and desert plant communities of the southwestern United States. The species forms a sprawling thicket and is very spiny: its green leaves dry out, the leaf tissue falls away, and the remaining veins harden into sharp spines. When in leaf, the bush has green, hairy stems, and produces yellow daisy-like flowerheads that grow in the axils, the upper angles, of the newest branches. The plant releases its fruit in masses of cottony seed. There are two recognized varieties of this species: Tetradymia axillaris var. axillaris and Tetradymia axillaris var. longispina. These varieties grow together in some locations, and their characteristics may intergrade where they overlap. Kawaiisu Native Americans of California historically used the plant's sharp spines as tattooing needles.
