Hoary tansyaster (Machaeranthera canescens) belongs to the Asteraceae (the Aster family). It is an annual or short lived perennial herb that is native to western and central North America. This herb grows in many habitats and in deserts, and up to 10-50 cm tall. It is a woolly-haired, glandular herb with one or more branching stems. The leaves are linear to oblong, 10 cm long near the base of the stems. Their edges usually serrated. In most regions, it blooms relatively late in the year, at the end of summer into the fall, though flowers appear in spring in the desert regions. The flower head has a center of many yellow disc florets and a fringe of blue or purple ray florets each 1-2 cm long. The fruit is an achene around 3 mm in length tipped with a pappus of long hairs.