Psilostrophe cooperi aka Cooper's Paper Daisy

Psilostrophe cooperi is a small shrub in the daisy family, Asteraceae. Its native range spans the southwestern United States and northwestern Mexico. It forms a dense, rounded plant with a woody base. The shrub reaches about 2 feet [0.6 metres] tall. It often grows from one short, woody trunk. This gives the plant a clear central base beneath its branches.

The bark ranges from reddish brown to grayish brown. As it develops, darker, scaly ridges mark its surface. Young twigs look quite different from the older bark. They are slender and round, with a gray-green surface. Dense hairs cover these young stems. The contrast between young shoots and older bark helps show the plant's woody form. Both the leaves and young twigs share a gray-green color and dense hair cover.

The leaves are simple, with one blade rather than separate leaflets. They grow in an alternate pattern along the stems. Each leaf is very narrow and can reach 4 inches long. Dense hairs cover the gray-green blades. The plant sheds its leaves in response to drought. Its foliage is therefore not a fixed, year-round feature. The narrow blades contrast with the shrub's dense, rounded outline. Leaf shape, hair cover, and drought-related leaf loss help describe its foliage.

Bright yellow flower heads appear from March through September. Each head looks like a small daisy. It measures about three-quarters of an inch across. The heads grow singly at the tips of branches. Their place at the shoot ends sets them apart from the leaves. The flowers dry rather than dropping away at once. As they dry, they gain a thin, paper-like texture. These dried heads remain on the plant beyond the fresh flower stage.

The fruits are light brown achenes with soft, fluffy tufts. An achene is a dry fruit that holds one seed. The tufted fruits differ in texture from the narrow, hairy leaves. Dried flower parts remain even after the seeds disperse. The shrub can thus retain traces of flowering after fruiting ends. Its yellow blooms and lasting dry heads mark separate stages. Together with the gray-green shoots, they define much of its visible form.