Encelia frutescens, Button Brittlebush
Scientific Name: Encelia frutescens
Common Name: Button Brittlebush
Also Called: Bush Encelia, Green Brittlebush, Rayless Encelia (Spanish: Hierba del Bazo, Rama Blanca)
Family: Asteraceae, Sunflower Family
Synonyms: (Simsia frutescens, Encelia frutescens var. frutescens, Encelia frutescens forma virginensis, Encelia frutescens var. virginensis)
Size: Up to 4 feet or more.
Growth Form: Shrub or subshrub; rounded with multiple slender stems from several short trunks, whitish, erect, slender, new stems glabrous, older stems have fissured bark.
Leaves: Green, gray-green; elliptic or narrowly ovate; mostly alternate; cauline; variable, simple with petioles, drought deciduous, rough with small stiff coarse hairs (strigose).
Flower Color: Yellow, mostly disk flowers, ray flowers less common, solitary flower heads ¾ inches on tips of long stalks or peduncles; peduncles strigose; phyllaries lanceolate; fruit an airborne achene.
Flowering Season: January to September in Arizona; February to May and again August to September in California.
Elevation: Up to 4,000 feet; up to 2,500 in California.
Habitat Preferences: High deserts, rocky slopes, desert washes, flats, slopes, mesas and roadsides.
Recorded Range: Encelia frutescens is found in the southwestern United States in AZ, CA and NV and also in Baja California and northwest Mexico. In Arizona it is found throughout much of the state although few records for the central east and the southeast areas.
North America & US County Distribution Map for Encelia frutescens.
U.S. Weed Information: No data available.
Invasive/Noxious Weed Information: No data available.
Wetland Indicator: No data available.
Threatened/Endangered Information: No data available
In the southwestern United States: Arizona, Nevada and Utah each have 4 species of Encelia, California has 5 species, New Mexico has 2 species and Texas has 1 species. All data is approximate and subject to taxonomic changes.
Comments: Button Brittlebush is primarily a Mohave Desert species and also found in the higher elevations of the Sonoran Desert. It may start blooming early in January and continue well into September following sufficient monsoon rainfall. Button Brittlebush is an important food source for the Desert Tortoise in periods of low moisture. Seeds are eaten by birds and small mammals.
The type species for Encelia frutescens is from Agua Caliente, Maricopa County (Emory in 1846), Arizona.
Button Brittlebush is closely related to Brittlebush which has cymose or panicled flower heads with a mostly smooth (glabrous) inflorescence and its leaves are densely whitish. Button Brittlebush has solitary heads and pubescent (strigose) stems and the leaves are not whitish.
In Southwest Desert Flora also see similar species: Brittlebush, Encelia farinosa, Virgin River Brittlebush, Encelia virginensis, Hairy Desertsunflower, Geraea canescens and Parish's Goldeneye, Bahiopsis parishii.