Chapparal

VI. PLANT COMMUNITIES
A. CHAPPARAL

Chaparral communities are found on several continents - in the Mediterranean, the African Cape region, central Chile, and southwestern Australia. In California, chaparral communities occur between 200 and 5000 ft. elevation and cover about ten million acres. Although their species composition varies from continent to continent, there are certain characteristics which are universal. The term "chaparral" derives from the Spanish chaparro, which is a thicket of shrubby evergreen oaks or a low-growing type of vegetation. In some references, particularly older ones referring more specifically to the chaparral communities of southern California, chaparral is referred to as "hard chaparral" (vs. "soft chaparral" or coastal scrub). Some references use "brushlands" for both chaparral and coastal scrub. In other documents, chaparral is a broad classification within which there are as many as 28 types such as chamise chaparral or "chamisal," mesic serpentinite chaparral, mesic north slope chaparral, scrub oak chaparral, coastal sage - chaparral scrub, and poison-oak chaparral.

Chaparral vegetation is typically an impenetrable entanglement of mostly four- to twelve-foot tall evergreen woody shrubs and/or dwarf trees. There is rarely much of an understory save an occasional soap plant (Chlorogalum pomeridianum) or melic grass (Melica spp.). A chaparral community is composed mainly of species which are adapted to seasonal and periodic drought by having sclerophylls (hardened leaves). Some of these sclerophyllous plants have reduced, needle-like leaves, e.g., chamise (Adenostoma fasciculatum), others have larger ones, e.g., manzanita (Arctostaphylos spp.). Some of the plants lose their leaves during prolonged droughts. Although many species may be dominant in chaparral communities, very few associated or understory species are found. Absent also are seedlings of those chaparral species already represented. This may be because many of the dominant species have high concentrations of compounds in their foliage which function as allelopathogens, phytotoxins that effectively suppress the germination and/or growth of other plants, thereby eliminating competition for water and nutrients. The dominant species are mostly spring-active, in other words they photosynthesize and grow in the spring, when rains have been able to penetrate deeply enough into the soil to become available to their roots. Under arid conditions, chaparral plants produce more fine roots than leaves and, although the plants may be evergreen, the fine roots are shed yearly in the hot, dry season. These species tend to be dormant in the summer.

Chaparral plants are highly adapted to periodic natural fires which occur once every ten to thirty or more years. Recent studies suggest that the role of fire in these communities may be of recent origin, shaping them beyond the effects of the Mediterranean climate. Some studies suggest that fire can benefit the chaparral community. The older the chaparral, the more monotypic (single-species) and fragile it becomes. As long as fire does not occur too frequently, it has the potential to rejuvenate chaparral by encouraging the growth of numerous species which might have been excluded in the years immediately preceding the fire.

One of several fire adaptations of chaparral plants is their ability to produce seeds at an early age. This occurs in some species of manzanita (Arctostaphylos) and buckbrush (Ceanothus) that do not resprout from woody plant parts.

Another fire adaptation is seed dimorphism: some chaparral plants produce two types of seeds, one that germinates under "normal" conditions and one which requires scarification, or the heat of a fire, in order to germinate. The latter seed type is called a "refractory" or "resistant" seed. It may remain viable for decades. Both chamise (Adenostoma fasciculatum) and deerweed (Lotus scoparius) produce two types of seeds. Recent studies suggest that charcoal residues in the soil are more influential on seed germination than heat alone.

Fire reduces the levels of organic nitrogen in the soil, but makes what nitrogen is present more available to plants. Many leguminous plants (pea family) and Ceanothus spp. have nodules on their roots which use nitrogen extracted from the atmosphere and fix it, that is they are able use it for their physiological processes as well as increase its levels in the soil around them. However, for approximately five years after fires the productivity of these plants is reduced.

Another fire adaptation found in some chaparral plants, such as some species of manzanita (Arctostaphylos) and chamise (Adenostoma fasciculatum), is their ability to sprout after a fire from underground woody plant structures called lignotubers (woody tap-roots), basal burls, or root-crown burls. These structures have vegetative buds located several inches below the soil surface which remain dormant until the winter rains following a fire. Also able to survive fire are western poison oak (Toxicodendron diversilobum) which has extensive underground rhizomes, and wild cucumber vine (Marah fabaceus) which has a huge fleshy root deep under the soil surface.

When chaparral areas are prevented from undergoing cyclical burns, so much biomass accumulates that the intensity of the inevitable fire can be sufficiently extreme to destroy the subsurface plant structures (seeds and/or buds on lignotubers and root-crown burls). Thus, the natural pattern of succession is broken. To avoid the problems associated with this, some biologists recommend burning chaparral areas at least once every twenty years. However, this is somewhat controversial. If a site is burned too frequently, it may be transformed into a specific type of chaparral called chamisal - a chaparral whose main component is chamise (Adenostoma fasciculatum). Alternatively, it may even fail to regenerate at all as chaparral. A burned chaparral stand may be transformed into a coastal scrub or a grassland composed mostly of annual non-native species.

Disturbance, by fire or otherwise, in chaparral is often made evident by the presence of invasive coastal scrub species such as black sage (Salvia mellifera), a prominent shrub in both the coastal scrub and chaparral of Poly Canyon. Other early successional species are deerweed (Lotus scoparius) and, especially in steep, rocky areas, sticky monkeyflower (Mimulus aurantiacus).

Some chaparral-dominated areas in Poly Canyon occur on serpentinite and the soils derived from it. The ecology of such areas is more fully discussed above, in the geology and soils section, and below, in the section on serpentinite communities. Serpentinite tolerant species found in chaparral communities in Poly Canyon include chamise (Adenostoma fasciculatum), toyon (Heteromeles arbutifolia), and buckbrush (Ceanothus cuneatus). Serpentinite endemic species include Obispo manzanita (Arctostaphylos obispoensis), leather oak (Quercus durata), and a species planted in the Botanic Garden in Poly Canyon, but native on Cuesta Ridge a few miles away, Sargent cypress (Cupressus sargentii).

In Poly Canyon, chaparral is most often found on the uppermost slopes and hilltops. It is bordered by grasslands, coastal live oak woodland, coastal scrub, rock outcrops, and anthropogenic communities. It is often tightly intertwined with coastal scrub, forming a complex patchwork on many of the hillsides.

Dominant plants of the chaparral include:: Chamise, greasewood (Adenostoma fasciculatum, Rosaceae); Buckbrush, California lilac(Caenothus cuneatus, Rhamnaceae); Birch-leaf mountain mahogany (cercocarpus betuloides, Rosaceae); Flannelbush, Fremontia (Fremontodendron californicum ssp. californicum , Sterculiaceae); *Toyon, Christmas berry (Heteromeles arbutifolia, Rosaceae); Islay, holly-leafed cherry (Prunus ilicifolia, Rosaceae); *Leather oak (Quercus durata, Fagaceae); *California coffeeberry (Rhamnus californica, Rhamnaceae); *Spiny redberry, Buckthorn (Rhamnus crocea, Rhamnaceae); *Black Sage (Salvia mellifera, Lamiaceae); *Western poison oak (Toxicodendron diversilobum, Anacardiaceae)
Associate species include:: Soap plant, amole (Chlorogalum pomeridianum, Liliaceae); Prickly, Phlox-leafed bedstraw (Galium andrewsii, Rubiaceae); *Climbing bedstraw (Galium porrigens, Rubiaceae); *California peony (Paeonia californica, Paeoniaceae)

Descriptions of Poly Canyon's chaparral plants follow.

Chamise, greasewood (Adenostoma fasciculatum, Rosaceae) This is an evergreen shrub that grows to 4 m. (12 feet) tall. Chamise has 4- to 10-mm. (1/8-to 1/2-inch) needle-like leaves in fascicles. Its tiny creamy white flowers are found in 4- to 12-cm. (11/2- to 5-inch) clusters at the tips of branches. Chamise blooms from May through July. Its fruit is an achene. It is indifferent to serpentinitic soils and is found primarily in chaparral communities and on dry slopes and ridges.

Adenostoma comes from the Greek aden meaning "a gland" and stoma "mouth," referring to the five glands at the mouth of the sepals. Fasciculatum refers to the arrangement of the leaves in bundles calles "fascicles."

The hard wood of chamiso has been used by Chumash in the manufacture of various tools. The leaves were made into tea for childbirth or menstrual complications.

Charles Webber

Buckbrush, California lilac (Ceanothus cuneatus, Rhamnaceae) Buckbrush is an evergreen shrub that grows to 3 m. (10 feet). Its 3-cm. (1/4-inch) cuneate-obovate leaves are thick and somewhat hard. The tiny white, pale blue, or lavender flowers are found in dense, 21/2-cm. (1-inch), raceme-like umbels from March through May. Its 4- to 6-mm. (1/8- to 1/4-inch) fruit is a three-horned, thick, green-red capsule. Buck brush is indifferent to serpentinitic soils. It occurs on dry slopes and ridges in chaparral communities. Ceanothus species host nitrogen-fixing bacteria.

Ceanothus means "spiny plant." Cuneatus refers to the wedge-like shape of the leaves.

Chumash used the flowers for hair and body shampoo by rubbing them with water to form a lather.

Birch-leaf mountain-mahogany (Cercocarpus betuloides var. betuloides, Rosaceae)

This evergreen shrub or tree grows typically to between 2 and 8 m. (6 and 24 feet tall). Its 1- to 5-cm. (1/2- to 2-inch) leaves are obovate to oval shaped with margins that are finely serrate above the middle and entire from the middle to the base. The leaves are pinnately veined with four to seven lateral veins. The greenish radial flowers have an 8-mm. (1/4-inch) apetalous, funnel-shaped hypanthium. The blooms appear from March through April. The fruit is a hairy, cylindric achene with the long, plumose style still attached. Birch-leaf mountain-mahogany is indifferent to serpentinitic soils and is found in chaparral communities on dry, rocky slopes.

Cercocarpus comes from the Greek, kerkos meaning "tail" and karpos meaning "fruit." This refers to the tailed appearance of the fruit to which the style remains attached. Betuloides means "birch-like."

Palo fiero (iron wood or stick, in Spanish) was used by Chumash as a digging tool.

Flannelbush, Fremontia (Fremontodendron californicum ssp. californicum, Sterculiaceae) Flannelbush is a 2- to 5-m. (6- to 15-foot) tall evergreen shrub or tree. Its branches and leaves are densely covered with stellate hairs. Its soft, leathery leaves grow to between 1 and 5 cm. (1/3 and 2 inches). These are ovate in shape and palmately to pinnately lobed. The showy, 60-mm. (2-inch), radial flowers of the flannelbush are vivid yellow and sometimes have reddish margins. The fruit is a 2- to 4-cm. (3/4- to 11/2-inch) bristly capsule. Kruckeberg lists flannelbush as a serpentinite indicator. It is found in chaparral communities.

Fremontia means "Frémont's tree," after John C. Frémont, a 19th century explorer in the West. Californicum means "of California."

Flannelbush is in the Cacao family from which we get Cola and chocolate. The stellate hairs on its branches can be quite irritating to human skin.

*Toyon, Christmas berry (Heteromeles arbutifolia, Rosaceae) This is an evergreen shrub or tree that grows to 5 m. (16 feet) tall. It has 4- to 11-cm. (11/2- to 41/2-inch) leathery, elliptic to oblong leaves that are sharply toothed, with shiny tops and dull undersides. Its tiny white rotate flowers occur in panicles between June and August. Christmas berry has 5- to 10-mm. (1/4- to 1/2-inch) red berry-like fruit (pomes) from November through January. The timing of the fruiting makes it a very important food source for wildlife. It occurs in chaparral and oak woodland communities.

Heteromeles means "different apple." Arbutifolia refers to the similarity of the leaves to those of the Spanish madrone or strawberry tree, Arbutus unedo.

Toyon derives from the Costanoan name for the plant tottcon. Chumash used its berries for food. Its hard wood was fashioned into a variety of tools, used for fuel, and in rituals.

Islay, holly-leafed cherry (Prunus ilicifolia ssp. illicifolia, Rosaceae) Islay is an evergreen shrub or tree that grows to 9 m. (30 feet) tall. It has 2- to 14-cm. (3/4- to 51/2-inch) alternate, leathery, ovate, spiny-toothed leaves. Its tiny, rotate, white flowers cluster in dense racemes from April through May. These are followed by 12- to 18-mm. (1/2- to 3/4-inch) purplish red drupes. Islay is found in canyons and on slopes, in shrubland and woodland communities. Its flowers attract bees.

Prunus is the ancient Latin name for "plum." Ilicifolia means "holly-like leaves."

Islay comes from a Salinan Indian name, "slay." The fruit and seed were eaten by native Californians. The seed, once leached of hydrocyanins, was highly valued as a food. One hatfull of islay was worth two hatfulls of acorns; two and a half hatfuls of islay were worth one hatful of chia.

Charles Webber

*Leather oak (Quercus durata var. durata, Fagaceae) This evergreen shrub or tree grows from 1 to 3 m. (3 to 10 feet) tall. It has 11/2- to 3-cm. (1/2- to 11/4-inch) spiny, convex leaves. The leaves are hairy on both surfaces with small, stellate hairs. Male flowers are minute, cream-colored, and occur in catkins. Female flowers are solitary and axillary. They are followed by acorns which take one year to mature. Leather oak is restricted, for the most part, to serpentinitic soils within chaparral communities.

Quercus is the ancient Latin name for "oak," from which we derive "cork," a product of some species of oak. Quercus comes from two Celtic words: quer "fine" and quez "tree." Durata means "hard" in Latin and probably refers to the hardness of the leaves.

*California coffeeberry (Rhamnus californica, Rhamnaceae) This is an evergreen, upright shrub that grows to 5 m. (15 feet) tall. It has characteristically reddish twigs. Its 23- to 90-mm. (1- to 31/2-inch) leaves are shiny, dark green on the upper surface and a bright yellowish green on the lower surface. They are leathery and oblong with minutely serrate margins and prominent veins. The inconspicuous greenish or white radial 5-merous flowers occur in five to 60-flowered umbels nearly year-round. The inflorescence is followed by 10- to 15-mm. (1/4- to 1/2-inch) coffee-colored (when immature) or black berry-like fruits (drupes). According to The Jepson Manual, California coffeeberry does not tolerate serpentinitic soils. However, Kruckeberg writes that it is indifferent to serpentinitic soils. It occurs in chaparral, coastal scrub, and oak woodland communities.

Rhamnus is derived from the ancient Greek name for "buckthorn." Californica means "of California."

Chumash believed the berries of "yerba del oso" (bear's grass, in Spanish) to be toxic to humans, but not to bears. The leaves were rubbed on the skin to soothe rheumatism. Bathing in a decoction of leaves was said to soothe poison oak rash. The bark was used as a laxative. It has occasionally been called cáscara sagrada (Spanish for "sacred bark"), although this name is usually given to Rhamnus purshiana.

*Spiny redberry, Buckthorn (Rhamnus crocea, Rhamnaceae) This evergreen shrub reaches to 2 m. (6 feet) tall. Its branches are thorn-tipped. It has finely toothed 11- to 19-mm. (1/4- to 1/2-inch) elliptic to obovate leaves. These are shiny, leathery, and feather-veined and often occur in fascicles. The inconspicuous whitish to yellowish 4-merous flowers occur in clusters of one to six between March and April. The flowers are followed by 6-mm. (1/4-inch) red berry-like fruits (drupes). Spiny redberry is is indifferent to serpentinitic soils and is found in chaparral, coastal scrub, and woodland communities.

Rhamnus is derived from the ancient Greek name for "buckthorn." Crocea means "saffron-colored."

*Black sage (Salvia mellifera, Lamiaceae) This is a drought deciduous, 1- to 2-m. (3- to 6-foot) shrub. Black sage has very aromatic foliage; the odor clings to one's clothing long after brushing up against this shrub. The glandular leaves are 21/2 to 7 cm. (1 to 3 inches) long. Its 6- to 9-mm. (1/4- to 1/3-inch) pale blue-lavender bilabiate flowers occur in 11/2-to 4 cm. (1/2- to 11/2-inch) wide, tight, widely-spaced, ball-like clusters around the stem (whorls). They bloom from April through July. The fruits that follow are inconspicuous brown nutlets in groups of four. Black sage is serpentinite tolerant. It occurs in chaparral where it is seral, and in coastal scrub where it is a climax species. Its flowers attract bees.

Salvia comes from the Latin salveo meaning "to save" and refers to the medicinal uses of many salvias. Mellifera means "honey-bearing."

Native Californians valued the seed of black sage as food.

*Western poison oak (Toxicodendron diversilobum, Anacardiaceae) This deciduous perennial has highly variable growth habits: vine, ground cover, shrub. In chaparral it usually grows as an erect shrub. Its compound leaves have three leaflets. The terminal leaflet ranges in size from 1 to 13 cm. (1/3 to 5 inches) long by 1 to 8 cm.(1/3 to 3 inches) wide. Lateral leaflets may be half as long. Leaves appear shiny bright green or red in spring then turn dull green or dusty red in summer. The leaves are very resinous. They can be confused with blackberry leaves which also have three leaflets. However, western poison oak leaves and branches lack any spiny or hairy projections, and the leaflets tend to have more rounded tips. The tiny yellowish green flowers occur in racemose panicles from April through May. These are followed by 11/2- to 6-mm. (up to 1/4-inch) creamy white to brownish berry-like fruits (drupes) which are an important food for wildlife. Western poison oak is indifferent to serpentinitic soils. It occurs in canyons and on slopes in chaparral and woodland communities. TOXIC: This plant causes severe contact dermatitis.

Toxicodendron means "poison tree." Diversilobum refers to the various shapes the leaves take.

Yedra (or hiedra, ivy) was used by Chumash externally in cauterization and in the healing of skin disorders (warts, cancers, persistent sores). A decoction of its root was used internally to cure dysentery and diarrhea. Some remedies said to soothe the effects of poison oak rash include bathing in a decoction of mugwort (Artemisia douglasiana), coyote brush (Baccharis pilularis), or California coffeeberry (Rhamnus californica).

Associated species include:

Beatrice F. Howitt

*Soap plant, amole (Chlorogalum pomeridianum var. pomeridianum, Liliaceae) Soap plant is a perennial that grows from a 7- to 15-cm. (23/4- to 6-inch) white bulb which is covered by a mat of brown fibers. Its basal, wavy-margined leaves are 20 to 70 cm. (8 to 28 inches) long and 6 to 25 mm. (1/4 to 1 inch) wide. The erect inflorescence ranges in size from 50 to 250 cm. (11/2 to 8 feet) and bears 15 to 25 mm. (1/2- to 1-inch) flowers that are white. The flowers open in the evening and close by the following morning. Following the flower a 5- to 7-mm. (1/4-inch) stalked capsule with black seeds develops. Soap plant is indifferent to serpentinitic soils and can be found in chaparral, woodlands, and grasslands in Poly Canyon.

Chlorogalum is Greek for "green milk." Pomeridianum means "afternoon."

For Chumash, the bulb of soap plant had a variety of uses: personal and laundry washing suds, hide preparation, fishing aid (the bulb was crushed then mixed into the water of a quiet pool to stupefy the fish), and rituals. Also, its fibrous coating was made into hair and cleaning brushes. The young shoots were roasted and eaten.

Prickly, Phlox-leafed bedstraw (Galium andrewsii, Rubiaceae) This silvery green perennial grows low to the ground 5 to 22 cm. (2 to 9 inches) tall in small tufts or mats. Its 4- to 11-mm. (1/8- to 1/2-inch) bristly, lanceolate, thickish leaves occur in whorls of four. The leaves are sharp to the touch; their tips retain a single hair-like structure.The inconspicuous yellowish rotate flowers are followed by tiny double berries. Prickly bedstraw is a serpentinite-tolerant plant. It can be found on dry slopes and ridges in chaparral and open woodland communities, often beneath the canopy of larger plants.

Galium comes from the Greek and means "milk" which some species of Galium are said to curdle. There was a Dr. Andrews (a physician?) who collected plants in the mid-1800s after whom this plant may have been named.

*Climbing bedstraw (Galium porrigens var. porrigens, Rubiaceae) Climbing bedstraw is a 6- to 15-dm. (2- to 5-foot) perennial. It has slender, softly woody main stems that are prickly to touch. Its ovate to oblong leaves grow to 18-mm. (3/4-inch) and occur in whorls of four. The leaves are pointed, but not sharp to touch; their tips bear a single ephemeral hair-like structure. The minute yellowish to reddish rotate flowers are followed by equally inconspicuous double berries. Climbing bedstraw is found in chaparral and forest communities.

Galium comes from the Greek and means "milk," which some species of Galium are said to curdle. Porrigens means "becoming scaly," from porrigo "scurf, dandruff."

Brother Alfred Brousseau

*California peony (Paeonia californica, Paeoniaceae) This is an herbaceous perennial with 35- to 75-cm. (14- to 30-inch) branched stalks. Its leaves are deeply lobed or divided. Their upper surfaces are dark green, while their lower surfaces are pale. California peony flowers are dark maroon and edged in pink. Their petals are 15 to 25 mm. (1/2 to 1 inch) long. The blooms appear from January through April and are followed by 3- to 4-cm. (1- to 11/2-inches) dry fruits called follicles. California peony tends to avoid serpentinitic soils. It occurs primarily in chaparral and coastal scrub communities.

Paeon was the Greek physician to the gods. Californica means "of California."

Chumash made Peonia's roots into a tea which they used to treat menstrual disorders and neuralgias.