Tanseyleaf tansyaste (Machaeranthera tanacetifolia) belongs to the Asteraceae (the Aster family). It is a biennial herb that is native to the southwestern and central United States and northern Mexico. This grows in grasslands, desert scrubs, woodlands, streambeds, roadsides, disturbed areas, and up to a height of 60-80 cm. The leaves are fern-like multilobed. The one or more flower-heads bloom in the inflorescence from March to October. The flower-head has a center of many yellow disc florets and a fringe of many lavender to purple ray florets each 1 to 2 cm long. The fruit is a flat achene about 1 cm long including the pappus.