Gamochaeta stagnalis

Gamochaeta stagnalis, the desert cudweed, is a species of flowering plant in the family Asteraceae. It is native to Mexico, Guatemala, and the southwestern United States.
Gamochaeta stagnalis is an annual herb up to tall, producing a slender taproot. Leaves are up to long. The plant forms many small flower heads in tightly packed clumps. Each head contains 3–4 purple disc flowers but no ray flowers.
Gamochaeta stagnalis is very similar to G. purpureum and some G. stagnalis specimens have been misidentified as that species.