Machaeranthera asteroides (fall tansyaster) is a North American species of plants in the sunflower family. It is native to the southwestern United States (California, Arizona, Nevada, New Mexico, Colorado, Utah) and northern Mexico (Chihuahua, Sonora, Baja California).
Machaeranthera asteroides is a biennial or perennial herb with a woody taproot. It often grows in a clump of several stems. Ray florets in the flower heads are white or purple, and female. Disc florets are yellow and bisexual.
Varieties
Machaeranthera asteroides var. asteroides - California, Arizona, Nevada, New Mexico, Chihuahua, Sonora
Machaeranthera asteroides var. lagunensis (D.D.Keck) B.L.Turner Baja California; Laguna Mountains in San Diego County in California
Machaeranthera asteroides var. glandulosa B.L.Turner - Arizona, Nevada, New Mexico, Utah