The chaparral ecosystem in California is comprised of a dense and diverse collection of small to mid-sized woody shrubs. It covers the hills in a shallow cloak of gray-green vegetation just thick enough to soften the contours of the land, but not to hide them. In some places the chaparral is dense and thick, so much so that it is nearly impossible to penetrate it, other places it is sparse and low. Animal trails riddle the chaparral and the bones of the land show through with a dramatic abruptness.
Sandstone outcrops above a chaparral covered hillside at Red Rocks State Park in Topanga
Chaparral grows primarily in dry, hot areas, as such the plants have a number of moisture saving adaptations that are most easily seen in their leaves which tend to be either small or waxy, or both in many cases. The ecosystem is surprisngly diverse in both plants and animals, but despite this there are a small handful that are common from Mexico through most of California and that, taken together, could be considered to be the background matrix of chaparral plants. Sage (Artemisia) and Ceanothus both are broad genus level plants with many individual members.
These plants are common in the chaparral, and taken with another extremely common plant, Chamise (Adenostoma fasciculatum), comprise what I think of as the matrix plants for the California wide chaparral.
Chamise (Adenostoma fasciculatum) flowers are small and clustered in tight bundles at the tips of the branches
Chamise, also known as greasewood, is in the rose family and produces clusters of small white flowers that look much like another rose family genus, Spiraea, which includes hardhack and meadowsweet. The flowers set seed and dry on the branch, remaining affixed to the stalk for several seasons after blooming.
The leaves of Chamise are needle-like, clustered in little bundles called fascicles, the word the scientific name derives from. On the whole, the plant looks something like a cross between rosemary and juniper with shredding bark, gnarled limbs, and and regularly placed leaf clusters.
Old Chamise plant on a ridge in the Santa Monica Mountains
Like many chaparral plants Chamise seeds require fire to germinate. This ensures that the seedlings will be able to take advantage of the temporary increase of nutrients and open sunlight in the plant’s early stages of growth. Estimates of the longevity of Chamise vary, but range from 100-200 years.
Chamise is not generally considered to be good browse for animals, but it is common to find extensive patches of heavily browsed plants. In some places the browse is so heavy that the bushes look like sculpted hedges, in other places they look like carefully trimmed bonsai trees.
Browsed Chamise branches
When it has not been browsed Chamise produces a relatively dense growth of vertical shoots. Over time many of these will die, with the dead stalks being retained by the plant. Some estimates of the total volume of retained deadwood on old plants reaches 60-70%, greatly adding to the potential combustibility of the Chamise.
Young Chamise branches
California Buckwheat (Eriogonum fasciculatum) can sometimes be mistaken for Chamise by the casual eye, but the leaves are broader and flatter and the flower structure is very different.
California Buckwheat (Eriogonum fasciculatum)
Chamise is found primarily in California, though northwest Mexico and western Nevada also host populations of this plant. Within California it is found in nearly all of the chaparral habitats as is shown on the digital Jepson Herbaria hosted by UC Berkeley.
Chaparral types with Chamise
This is a tough plant. It grows with little water, on hard, rocky soil, and can even grow in serpentine soils, a soil type that kills many plants. Many people do not like Chamise due to its flammability, but it is an excellent erosion control plant, provides cover for a number of birds and small animals, and serves as a last resort browse as well.
It is not the only chaparral plant by any stretch, nor even the most typical in any given area, but it is the one I have seen in the most places through California.
Writing for Nature 