Machaeranthera arida
| Machaeranthera arida | |
|---|---|
 | |
| Scientific classification | |
| Kingdom: | Plantae |
| (unranked): | Angiosperms |
| (unranked): | Eudicots |
| (unranked): | Asterids |
| Order: | Asterales |
| Family: | Asteraceae |
| Genus: | Machaeranthera |
| Species: | M. arida |
| Binomial name | |
| Machaeranthera arida B.L. Turner & Horne | |
| Synonyms | |
|
Arida arizonica | |
Machaeranthera arida (syn. Arida arizonica) is a species of flowering plant in the aster family known by the common names arid tansyaster, desert tansyaster, and Silver Lake daisy. It is native to the deserts of northern Mexico and the southwestern United States, where it is widespread throughout desert habitat, including disturbed areas such as roadsides. It is an annual herb with a branching stem reaching 30 centimeters tall. The oblong leaves are up to 3 centimeters long, edged with bristly teeth, and sometimes divided into lobes. The herbage is coated with glandular rough hairs. The inflorescence bears one or more flower heads lined with glandular phyllaries. The head has a center of many yellow disc florets and a fringe of lavender or white ray florets each a few millimeters long. The fruit is a hairy achene between 1 and 2 millimeters long. Fruits from the disc florets generally have pappi.