Coastal scrub communities occupy a narrow discontinuous band along the coast of California.  In southern California, these communities extend into the foothills of the Transverse and Peninsular Ranges.  These communities are found over a elevational range from near sea level to over 2,000 feet.  In northern California, coastal scrub communities are found mostly at lower elevations. In southern California, they occur at lower elevations along the coast and at higher elevations inland on mountain slopes.
 
Coastal scrub communities are found in climates varying from moist to dry. In northern California, coastal scrub communities recieve up to 200 cm (80 in) of rainfall each year;  however, in central and southern California they occur in dryer areas that range from about 50 cm (20 in) of annual precipitation to as little as 23 cm (9 in) in San Diego.  Coastal scrub communities extend further south into northern Baja California where they are found in very arid conditions and grade into desert communities.  So as you might expect, the species composition of coastal scrub communities vary signifantly from northern to southern California.  Poly Canyon and central California occurs in an intermediate area in which some species from northern California mix with those typical of southern California.  This makes the coastal scrub areas found locally some of the most diverse the the state.
 
Northern coastal scrub communities are dominated by evergreen shrubs one to two meters tall often with a well developed herbaceous or low-woody understory.  In most stands, the dominant species is either Baccharis pilularis (coyote bush) or Lupinus arboreus (tree lupine).  Coyote bush is found throughout the entire range of coastal scrub communities.  Common species in the north include Rubus ursinus (blackberry), Toxicodendron diversilobum (poison oak)  Mimulus aurantiacus (bush monkey flower), Eriophyllum staechadifolium (coastal-golden yarrow), and Gaultheria shallon (salal).
    
Southern coastal scrub communities occur from the San Francisco Bay area south to Baja California. Most plants of southern coastal scrub communities are adapted to arid conditions and have shallow root systems that permeate the upper soil horizons.  The dominant plants are usually shrubs with soft stems and leaves.  Growth in these communities occurs in the winter and spring when moisture is available. In summer months when soils dry out, the dominant plants loose some or all of there leaves and terminal portions of the stems die back. Photosynthesis and plant growth occurs at high rates during the winter-spring growing season and the plants go into a form of dormancy in the dry summer months. Along with these drought deciduous species, there are a few evergreen species such as coyote bush and coffee berry.  Common species include Artemisia californica (California sagebrush), Mimulus aurantiacus (bush monkeyflower), Salvia spp. (sages) Lupinus spp. (bush lupines), and Eriogonum fasciculatum (California buckwheat )
 
An interesting aspect of this community is that many of the shrubs have foliage high in scented oils and chemicals (terpenes) that volatilize into the air and settle in the soils below.  As you walk through this community the highly scented sages and California sagebrush are obvious.  Break a leaf of one of these plants and smell!  These volatile compounds once in the soil often inhibit the growth of herbaceous plants.  Consquently, it is not uncommon to see very little understory vegetation in the coastal scrub communities.  .

The coastal scrub communities occur in several patches on the steep, rocky hillsides surrounding Poly Canyon.  Coastal Scrub usually forms a mosaic with the grassland and also integrates with the coast live oak woodland and to a lesser extent the riparian woodland where they form part of the understory vegetation.

The relative species composition of the coastal scrub stands vary from site to site. In more favorable sites, coastal scrub is composed of a diversity of shrubs.  On the driest, rocky areas Yucca and California buckwheat along with Selanginella (spike-moss or resurrection plant) are dominant.  Rocky areas dominated by Yucca whiplei (yucca) are sometimes referred to as Yucca scrub, an arid form of coastal scrub.

The most common species of the coastal scrub communities are listed below.  Click on each one to view a photgraph.

Artemisia californica (california sagebrush)
Baccharis pilularis (coyote bush)
Eriogonum fasciculatum (California buckwheat)
Salvia mellifera (black sage)
Yucca whipplei (yucca)
Mimulus aurantiacus (sticky monkey flower)

Common Associates include:
Lotus scoparius (deerweed)
Toxicodendron diversilobum (poison oak)
Hazardia squarrosa (sawtooth goldenbush)
Lupinus albifrons (bush lupine)
Marah fabaceous (manroot)
Ribes speciosum (fuchsia flowered gooseberry)
Sambucus mexicana (elderberry)