(Photograph = Encelia farinosa flowers, Chipmunk)
Introduction
Encelia farinosa (brittlebush) is a drought-deciduous shrub of the Mojave and Sonoran deserts and nearby foothills in the southwestern United States and northwestern Mexico. It is most common below about 1,000 m on rocky slopes, washes, road cuts, and other open, disturbed ground. Compared with the coastal species E. californica, this inland species has silvery, tomentose leaves that reflect sunlight and reduce water loss. After fires or grading, it often colonizes quickly and is sometimes hydroseeded for erosion control.
The Details
Form and leaves: Plants are rounded and much-branched, usually 0.5–1.5 m tall. Leaves cluster near the tips of young shoots and are conspicuously fuzzy; in wet spells, new leaves are thinner and less hairy, then thicken and shed as soils dry. Stems are brittle—hence the common name.
Flowers and varieties: Heads have yellow rays surrounding yellow disc florets. A distinctive variant, var. phenicodonta, bears purple-brown disc florets along parts of the lower Colorado and Salt rivers and in Baja California. Bloom typically follows cool-season moisture from late fall into spring.
Ecology and regeneration: Root systems are generally shallow, suited to rapid use of brief wet periods. In some desert scrub, brittlebush increases after fire and can dominate early post-fire stands; over time, other shrubs re-enter as fuels and rainfall patterns allow. On sites with ongoing disturbance or open, gravelly soils, it persists as a common component.
Range notes and look-alikes: Within California, records concentrate in the deserts and interior valleys; to the north and east, it reaches southwestern Utah and western Arizona, and it extends into northwestern Mexico, including Baja California. Hybrids with E. frutescens occur locally and can complicate identification.
Additional Information: Flor de Rocío (Encelia farinosa)
