Leafy Common Rabbitbrush, which is now called by the scientific name Ericameria nauseosa and was formerly referred to as Chrysothamnus nauseosus also has the common names of chamisa, rubber rabbitbrush, and gray rabbitbrush. It is a perennial North American shrub in the sunflower family or Aster family (Asteraceae) along with sagebrush, with which it is often found.
Rabbitbrush was moved from the genus Chrysothamnus to the genus Ericameria in a 1993 paper, and the findings of a 2003 phylogenetic investigation of Ericameria were consistent with the move of the rubber rabbitbrush from Chrysothamnus to Ericameria.
It is found in several places within San Bernardino County, including in the Angeles National Forest in the San Gabriel Mountains and the San Bernardino Mountains. It proliferates particularly at various points along the trail from the Mt. Baldy Notch and the tree line on the east peak of Mt. San Antonio.
Rubber rabbitbrush is highly variable, with several different subspecies located throughout the western United States. It is typically distinguished by having whitish to green flexible stems, felt-like matted hairs, and narrow, thread-like grayish-green alternate leaves. Shrubs are rounded and generally two to five feet tall, with some reaching as high as eight feet. Flower heads are made up of 5 small, yellow, tubular disk flowers flowers, in dense, umbrella shaped, rounded or flat-topped terminal clusters. Flowers bloom from August to October, such that they come into fluorescense just as many other plants are fading, providing vivid color and a pollen source for insects late in the summer.
The golden-yellow flowers are pungent-smelling. Indeed, the species name “nauseosa” refers to the smell given off when the leaves or flowers are crushed, though they seem to produce an olfactory sensation that varies from individual to individual. Some describe it as pineapple-like; others say it is foul and rubbery.
Leaves, depending on the subspecies, are long and narrow to spatula-shaped. Both the flexible, ie., rubbery stems and the leaves are greenish-gray with a soft felt-like covering.
The shrubs reproduce via an abundance of small and light, wind-dispersed seeds. They often sprout from the base.
This plant can flourish and thrive in poor soil and precipitation conditions that the vast majority of plants cannot tolerate. They can grow in coarse, alkaline soils.
Leafy common rabbitbrush occurs as a dominant to minor component in many plant communities, ranging from arid rangelands to montane openings. Dense stands are often found on degraded rangelands, along roadsides, and in abandoned agricultural fields. Possessed of a deep root system, this plant establishes quickly and plants produce large quantities of leaf litter, helping to bring nutrients to the soil surface from the deeper rooting profile.
The forage value of rubber rabbitbrush varies greatly among subspecies and ecotypes. Along with associated species, like big sage and western wheat grass, rubber rabbitbrush is a significant source of food for browsing wildlife on fall or winter ranges, such as mule deer, pronghorn, and jackrabbits. It also provides cover for mammals and small nesting birds. Livestock generally forage only lightly on this species and it is considered to be of little value to all classes of livestock.
The Zuni Tribe and some other native Americans reportedly used rabbitbrush as a yellow dye, to make a medicinal tea, and for chewing gum. The Zuni people used the stems to make baskets.
The plant has chemical potential in a modern industrial context. The common name rubber rabbitbrush refers to the rubber content in the sap, which varies by subspecies. Rabbitbrush was first tested as a source of high quality rubber during World War II. In recent decades, there has been renewed interest in its potential for production of rubber, resins, and other chemicals, and is considered to be a promising
source for hypoallergenic rubber for use in products designed for people with latex allergies. Compounds in rubber rabbitbrush are being evaluated for nematocides, anti-malarial properties, and insect repellents. Currently the University of Nevada is conducting research on possible of uses of rubber rabbitbrush for biomaterial and bioenergy and biocrude fuels.
The species is useful in soil stabilization and restoration of disturbed sites. In the wake of California’s current drought, it has gained popularity as an ornamental xeriscaping shrub in areas where water conservation is important. The white/gray foliage, abundant flowering, and tolerance for poor conditions makes it well suited for desert landscaping.