Most of the year, coyote brush (or chaparral broom, Baccharis pillularis) can be recognized by its bright green foliage. In the fall, however, plants are covered with white as the shrub releases thousands of tiny seeds, each carried away in the breeze by a delicate, silken parachute.
Other Common Names:
Coyote brush is a perennial shrub usually less than 10 feet (3 m) tall, with numerous, ascending branches. A prostrate form exists in some coastal areas, but not in the Reserve. Coyote brush has an extensive root system, with a taproot that may extend 10 feet (3 m) and a well-developed lateral system.
Leaves are bright green, resinous, variable; usually less than 1 inch (2.5 cm) long, and broadest at tip. Margins are entire or with a few jagged teeth. Leaves have a waxy coating and contain resinous oils.
Plants bear male and female flowers on separate plants (dioeceous). Male and female flower heads are disk florets, clustered into small, green-white flower heads toward the ends of branches. Although individual flower heads are small and inconspicuous, the sheer masses may color the shrub white or creamy. Blooms occur between August and December1 and are pollinated by a wide variety of insects.
Seeds are less than 1/16 inch (2 mm) in length, each with a tuft of long bristles (the pappus) that serves to disperse seeds through the air. A shrub dispersing the plumed seeds is conspicuous.
Coyote brush is native west of the Coast Ranges below 2000 feet (600 m) from southern Oregon to northern Baja California, and on the Channel Islands. It may dominate coastal sage scrub vegetation but is found in a number of other vegetation types. It often colonizes disturbed areas.
The genus is distributed globally.
Coyote brush is common in the Reserve, especially in the coastal sage scrub.
Coyote brush is a dicot angiosperm in the sunflower family, the Asteraceae. This is the largest family of vascular plants in the Northern Hemisphere.143 “Flowers” of Asteraceae are made up of one or both of two types of flowers (florets): symmetrical disk florets and strapped-shaped ray florets. These are crowded onto a common base (receptacle), and together are called a flower head,11,44,49 which is often assumed to be a single flower.
Other familiar Asteraceae that occur in the Reserve include such dissimilar flowers as bush sunflower (Encelia californica), goldenbush (Isocoma menziesii) and California sagebrush (Artemisia californica).
Baccharis is the only common Asteracea that has male and female flowers on separate plants.11 Species in the genus Baccharishave disk flowers only.
B. serathroides, also found in the Reserve,48 is similar to B. pilularis and hybrids between them are likely. One other Baccharisspecies, mule fat (B. salicifolia), is frequent in the Reserve, but prefers more riparian areas.
Two subspecies of coyote brush have been described, based largely on their growth form and habitat. Our subspecies is consanguinea, upright shrubs with somewhat brittle stems.48Jepson eFlora Taxon Page
Like many plants of dry regions, the waxy coating of coyote brush leaves retards water loss, while the resinous oils may deter grazing.25
Coyote brush colonizes disturbed areas, including post-burn areas. During natural fires the root crown often survives and later resprouts. Also, the numerous small, wind-born seeds have a wide dispersal area and good chance of landing in disturbed areas. However, while coyote brush serves as a nurse-shrub for a variety of other species, it is not tolerant of shade and is generally slowly displaced by more mature vegetation.5
Areas of the Reserve that were once disturbed by farming can be recognized by the high abundance of coyote brush. The area enclosed by the Gemma Parks trail and the area below the Sta. Carina trailhead are two such locations.
Coyote brush is somewhat resistant to burning, perhaps because of high concentrations of fire-retardant organic compounds in the leaves.25 Some local agencies recommend them for planting in fire prone areas.24 Under the right conditions, however, coyote brush will burn.5
The name “broom” is borrowed from the closely related B. serothroides in which terminal branchlets tend to be more upright and parallel, resembling little brooms. The Chumash Indians used clusters of branchlets of both species when collecting cactus to brush away the small spines,15 and early settlers used these to sweep and even (we are told) as toothbrushes.100
Chumash Indians applied boiled leaves as a remedy for poison oak.15
Because of its rapid growth, wildlife value, erosion control value, and fire resistance, coyote brush is used in native plant gardens and restoration projects.24,79 In general, only male plants are propagated, since many home owners object to the abundant white fluff that accompanies the seeds.
Coyote brush commonly supports bud galls created by the host- specific midge Rhopalomyia californica.22 These bud galls often resemble little cauliflowers or little cabbages or something in between. Galls offer protection and nutrition to the midge larvae while they mature, and they sometimes also support the competitors and predators of the midge.The specific name for coyote brush, pilularis, is Latin for having globules, which may refer to these spherical galls.21
The origin of the name “coyote brush” is unclear. One theory holds that the leaves may look like coyote paws; another that the plant is variable and adaptable – “clever, like a coyote”.25 A less imaginative theory suggests it was named because of an ecological association with coyotes.