Size: 2 feet (61 cm) tall or more and twice as wide
Growth Form:Forb/herb or subshrub; plants with a woody base; rounded over, mounded; stems and branches covered with a whitish felt-like wool (tomentose).
Leaves: Green, or gray-green; leaves narrow, linear; leaves arranged alternately along stem.
Flower Color: Yellow, bright- or pale-yellow; following bloom the 3 to 6 (8) rayflorets persist and become papery and fade to cream or whitish; flowers heads showy, 1 inch (2.54 cm); the inner diskflorets in the center of the head are tubular and bright yellow; flower heads mostly solitary clusters on the tips of branches; fruit is a gland-dotted cypsela with a pappus.
Flowering Season: February or March to September or later, mostly spring through fall but may bloom year-round.
Elevation: 2,000 to 6,000 feet (610-1,829 m)
Habitat Preferences: Lower and upper deserts, Creosote (Larrea) Bush communities, dry areas, rocky hillsides, mesas, plains, sand and gravel washes. Largest populations in AZ, southeast CA and southern NV.
Recorded Range: Found in the southwestern United States in AZ, CA, NV, UT. Also native to most of northern Baja California and northwest Mexico, Sonora.
Genus Information: In North America there are 5 species and 10 accepted taxa overall for Psilostrophe. Worldwide, The Plant List includes 7 accepted species names and a further 10 scientific names of infraspecific rank for Psilostrophe.
The genus Psilostrophe was published in 1838 by Candolle, Augustin Pyramus de (1778-1841).
In the Southwestern United States: Arizona, New Mexico and Utah each have 3 species of Psilostrophe, California and Nevada each have 1 species and Texas has 2 species. Data approximate and subject to revision.
Comments: Whitestem Paperflower is a common but showy plant so named because the yellow ray flowers that persist on the flower head after blooming, then turn tannish-yellow and papery in appearance.
Whitestem Paperflower will be found in both the Sonoran and Mojave Deserts.
Importance to Wildlife, Birds and Livestock
Whitestem Paperflower, Psilostrophe cooperi showy yellow ray and tubular flowers, and their seeds and plants may be visited by hummingbirds and/or small mammals including rodents and granivorous birds in search of food, nectar, shelter and protection through cover.
Beneficial Value to Butterflies, Bees and Insects
Whitestem Paperflower, Psilostrophe cooperi showy yellow ray and tubular flowers, and their plants may be visited by butterflies, moths, native bees and other insects in search of nectar and/or other food.
Etymology:
The genus “Psilostrophe” (Psilostro'phe:) from the Greek words ‘psilos,’ meaning “naked, glabrous” and ‘trophos’, meaning nourishment or nurse, alluding to the naked, epaleate (the "nurse"); a technical botanic reference to the receptacle lacking palea.
The genus Psilostrophe was published in 1838 by Candolle, Augustin Pyramus de (1778-1841).
