Dieteria asteroides, the 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).Biota of North America Program 2014 county distribution map
Dieteria 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.Wooton, Elmer Ottis & Standley, Paul Carpenter 1913. Contributions from the United States National Herbarium 16(4): 189 as Machaeranthera simplex
VarietiesFlora of North America, Dieteria asteroides Torrey in W. H. Emory, Not. Milit. Reconn. 141. 1848. Dieteria asteroides var. asteroides - California, Arizona, Nevada, New Mexico, Chihuahua, Sonora Dieteria asteroides var. glandulosa (B.L.Turner) D.R.Morgan & R.L.Hartm. - Arizona, Nevada, New Mexico, Utah Dieteria asteroides var. lagunensis (D.D.Keck) D.R.Morgan & R.L.Hartm. Baja California; Laguna Mountains in San Diego County in California
References
External links photo of herbarium specimen at Missouri Botanical Garden, collected in New Mexico, isotype of Machaeranthera simplex photo of herbarium specimen at Missouri Botanical Garden, isolectotype of Machaeranthera canescens var. latifolia A. Gray (syn of Machaeranthera asteroides var. asteroides