Dieteria canescens

Dieteria canescens, the hoary tansyaster, is a biennial or short-lived perennial herb of the aster family native to dry, open habitats across much of the western United States and adjacent Canada and Mexico, from Saskatchewan and British Columbia south to Texas, Arizona and California. It produces one or several slender, much-branched stems 20-80 cm tall that are clothed, like the rest of the plant, in dense, short, white-hoary hairs giving it a grey-green appearance. The alternate leaves are linear to oblanceolate, 1-6 cm long, with entire or sparsely toothed margins. From midsummer into autumn the stems bear a loose, open inflorescence of daisy-like heads about 2-3 cm across. Each head has 12-25 narrow pale-purple to violet ray florets surrounding a yellow disc, and the involucral bracts are arranged in several overlapping series, with the outer bracts often spreading or recurved at the tip.