The green growing world outside our windows is an incredibly diverse landscape of different plant species. It’s estimated that over 350,000 different kinds of plants exist worldwide.
Many hundreds of trees, shrubs, wildflowers and grasses populate OSA lands. They grow in recognizable groupings, or plant communities, that help distinguish one area from another. The most common plant communities found on OSA lands are chaparral, oak woodland, grassland, riparian and serpentine grassland.
The types of plants that thrive in a given location offer clues to the elevation, soil types, water availability, sun exposure and other resources available there. Being acquainted with plants can help you read the larger patterns of the natural world.
Now showing on OSA lands
Hound’s Tongue
Mayfair Ranch Trail
Rancho Cañada del Oro Open Space Preserve
Hound’s tongue is a native perennial herb with small blue flowers that grow on a central stem. The plant emerges in early spring with broad, bronze-colored leaves shaped like - you guessed it - a hound’s tongue.
After it blooms, the plant disappears in summer. Hound’s tongue is found in many areas of North America, usually growing on shady slopes. The roots were used by native Americans in preparations to treat burns and stomachaches.
Scientific name: Cynoglossum grande
How to say it: Sigh-no-GLOSS-um GRAN-dee
Pacific Pea
Mayfair Ranch Trail
Rancho Cañada del Oro Open Space Preserve
Pacific pea, a California native, is found at lower elevations throughout the state. A climbing vine, it is found most often in forest, woodland and chaparral environments.
Some Native Americans used the greens and seeds as a food source. A decoction from the roots was also used as a general tonic.
Scientific name: Lathyrus vestitus
How to say it: LA-thi-ris ves-TIE-tus
Shooting Star
Mayfair Ranch Trail & Catamount Trail
Rancho Cañada del Oro Open Space Preserve
A native perennial, shooting star is named for the shape of its blossom. Multiple hanging flowers cluster on a central stalk. Their petals flare upward, like the trail of a comet in space. Several species of shooting star are native to California and the western United States. The plant is a member of the primrose family.
Scientific name: Dodecatheon hendesonii
How to say it: doe-deh-KATH-ee-on hen-der-SONE-ee-eye
Miner’s Lettuce
Mayfair Ranch Trail
Rancho Cañada del Oro Open Space Preserve
One of the first green shoots of spring, this plant gets its common name from the Gold Rush miners who ate the tender leaves as salad greens. A California native, it grows primarily in woodland and forest environments, but can also be found in chaparral, scrub, and urban areas.
The early leaves are spade-shaped and develop at the end of long slender stems. Later, the more-recognizable round leaves develop, encircling the stem and its small white flower.
Scientific name: Claytonia perfoliata
How to say it: klay-TONE-ee-a per-fo-lee-AY-ta
Gooseberry
Mayfair Ranch Trail
Rancho Cañada del Oro Open Space Preserve
Gooseberry is most often found in chaparral and forest openings and is native to the Coast Ranges. In spring, small white to maroon flowers hang in clusters on this small shrub. The bush is summer or stress deciduous. Its spiky reddish berries attract many kinds of birds. The fruit was a food source for Native Americans, eaten both fresh and dried.
Scientific name: Ribes californicum
How to say it: RIE-bees ka-li-FOR-ni-kum
White Baby Blue Eyes
Mayfair Ranch Trail
Rancho Cañada del Oro Open Space Preserve
The common name says it all: this flower is a variety or subspecies of the more colorful baby blue eyes. A California native, white baby blue eyes is found in several other western states. It favors shady sites and is often found mixed in with tall grasses.
Scientific name: Nemophila menziesii ssp. atomaria
How to say it: nem-OF-il-a MEN-zees-ee-eye at-oh-MARE-ee-a
Shepherd’s Purse
Casa Loma Road staging area
Rancho Cañada del Oro Open Space Preserve
This plant gets its common name from the distinctively shaped seed pods that are prominent on the flower stalk. When ripe, they split in half to release numerous tiny seeds that are a food source for birds.
Shepherd’s purse is thought to have originated in Europe and has migrated around the globe, probably due to its many medicinal uses. The early spring leaves that appear before the flower stalks develop are tender and can be eaten in salads or cooked. Cultivated in some cultures as a food source, the plant is also considered by others to be a weed.
Scientific name: Capsella bursa-pastoris
How to say it: kap-SEL-la BUR-sa pas-TOR-is
Wedgeleaf Ceanothus
Catamount Trail
Rancho Cañada del Oro Open Space Preserve
Sometimes called buckbrush, this native perennial is an evergreen shrub. Spring flower clusters range in color from blue to white and usually appear from February to April.
Ceanothus is typically found in chaparral plant communities and is extremely drought tolerant. It ranges from Oregon to Baja California. Some Native Americans used ceanothus twigs in basket making.
Scientific name: Ceanothus cuneatus
How to say it: see-ah-NO-thus kew-nee-AY-tus
Blue Witch
Mayfair Ranch and Catamount Trails
Rancho Cañada del Oro Open Space Preserve
Blue witch is a small woody shrub that blooms in spring and develops green berries in early summer. Also called blue witch nightshade or blue nightshade, the plant contains solanine, a toxic alkaloid that may cause serious illness or death. No part of this plant should be eaten.
A California native, blue witch favors chaparral and woodland environments and is widely distributed in coastal and inland valley areas. It is also found in other western states.
Scientific name: Solanum umbelliferum
How to say it: so-LAY-num um-bel-IF-er-um
Red Maids
Mayfair Ranch Trail
Rancho Cañada del Oro Open Space Preserve
A low-growing spring wildflower, red maids are blooming now on warm, south-facing banks along the trail. Red maids are California natives that are also widely distributed in western lands from New Mexico to British Columbia. This annual herb is drought tolerant, likes full sun and is usually seen from February to April.
The leaves are edible and the seeds were a food source for Native Americans who toasted and ground them into meal. Birds, insects and small mammals also include red maid seeds in their diet.
Scientific name: Calandrinia ciliata
How to say it: kal-an-DRIN-ee-ah sil-ee-AY-tah
Milkmaids
Mayfair Ranch Trail
Rancho Cañada del Oro Open Space Preserve
This small white wildflower, topping a narrow stalk, is blooming in a number of woodlands along the trail. One of Santa Clara Valley's earliest wildflowers, look for it from January until April.
Milkmaids are a perennial herb native to California but also found in other western states. It grows most often in woodland plant communities.
Scientific name: Cardamine californica
How to say it: kar-DAM-in-ee ka-li-FOR-ni-kah
Indian Warrior
Catamount Trail
Rancho Cañada del Oro Open Space Preserve
A native perennial, Indian warrior is typically found in chaparral and woodland communities. It’s distributed from southern Oregon to Baja California.
The plant will grow as a root parasite it if gets the chance, taking water and nutrients from the host plant’s root. Manzanita is a frequent host in this relationship. The plant is often used as a medicinal herb.
Scientific name: Pedicularis densiflora
How to say it: ped-ik-yoo-LARE-us den-sih-FLOR-uh
California Buttercup
Longwall Canyon Trail
Rancho Cañada del Oro Open Space Preserve
The bright-yellow California buttercup blooming is an early-blooming wild flower, often found in sunny spots along the trail. This perennial blooms in abundance in Santa Clara Valley.
True to its name, California buttercup is native here but is also found in Oregon, Washington and British Columbia. Most members of the buttercup family are toxic in some way. California buttercup may produce a skin irritation in sensitive individuals.
Scientific name:Ranunculus californicus
How to say it: ra-NUN-kew-lus ka-li-FOR-ni-kus
Bristly Golden Aster
Bald Peaks Trail
Rancho Cañada del Oro Open Space Preserve
A California native, this perennial herb is found in central and southern portions of the state. In our region it favors foothill woodland, chaparral and grassland environments. The plant is sometimes called sessile false goldenaster; like other flowers in the Heterotheca family, it has hairy leaves and stems.
Scientific name: Heterotheca sessiliflora ssp. echioides
How to say it: het-er-o-THEE-ca seh-si-li-FLOR-a ek-ee-OH-i-dees
Oak-Loving Bolete
Longwall Canyon Trail
Rancho Cañada del Oro Open Space Preserve
As their name suggests, these mushrooms are found under oak trees, particular coast live oaks. They grow singly or in small groups and are usually reddish brown or maroon in color.
Mushrooms are fungi and belong to a separate biological kingdom. We’ve included them here, but they aren’t technically plants.
Mushrooms reproduce by spores in gills on the underside of the cap. The immature mushroom forms on an underground structure similar to the roots of a tree. It enlarges rapidly by absorbing water, which is why mushrooms seem to appear suddenly after a rain.
Scientific name: Boletus dryophilus
How to say it: bo-LEE-tus dry-OH-fil-us
Mistletoe
Mayfair Ranch Trail
Rancho Cañada del Oro Open Space Preserve
Mistletoe is the common name for more than a thousand species of plants that take water and nutrients from other plants they grow on. Because they have green leaves that can also make their own nutrients, mistletoe is sometimes considered to be hemi-parasitic.
The variety that grows on oak trees in the Bay Area is native to California but also found in other western states. The plants are either male or female, with the females producing small, sticky whitish berries that are attractive to many birds, including western bluebirds, robins, mourning doves, waxwings and even pigeons.
The dense tangle of stems the plant produces, often referred to as witches’ brooms, provide cover and nesting sites for a variety of bird species. Grazing mammals like elk and deer will eat mistletoe when fresh foliage is scarce. The plant also feeds bees and many other insects. It’s important to note that mistletoe is, however, toxic to humans.
Because it grows slowly, often without damage to the host plant; offers so many benefits to wildlife;, and has been part of its native ecosystems for thousands, perhaps millions, of years, many scientists feel that mistletoe is an environmental asset.
Scientific Name: Phoradendron villosum
How to say it: fore-a-DEN-dron vil-OH-sum
Purple Needlegrass
Llagas Meadow
Rancho Cañada del Oro Open Space Preserve
Besides being a California native, this perennial is the state’s official grass. It is widely distributed and provides a number of important benefits to the grasslands, woodlands and chaparral where it grows.
Being deeply rooted, the grass hold moisture in the soil, helping other plants like oak seedlings to survive. Purple needlegrass can live for 100 years or more and, once established, contributes to keeping invasive annual grasses in check.
Many species of wildlife feed on the grass. Its seed was also used by some Native Americans as a food source. Managed grazing, prescribed fire and reseeding have brought this important species back to the Llagas Meadow.
Scientific name: Nassella pulchra
How to say it: na-SEL-a PUL-kra
California Bay
Mayfair Ranch Trail
Rancho Cañada del Oro Open Space Preserve
Sometimes called California laurel or bay laurel, this tree has strongly aromatic leaves that can be used in cooking. The tree is an evergreen that is native to California and can grow to be 100 feet tall. With the winter rains new buds are just beginning to appear at the tips of branches.
Native Americans had uses for many parts of the tree. The nuts, which ripen in early fall, were eaten raw or roasted, or sometimes ground into a meal for bread making. The leaves were used to relieve headache and rheumatism and also to get rid of fleas and fumigate homes. Crushed, the leaves can give off a fragrance that is strong enough to be painful.
The leaves and twigs, especially new shoots, are browsed by deer and the seeds are eaten by birds and rodents. The tree also provides cover and nesting sites for a variety of birds.
Scientific Name: Umbellularia californica
How to say it: um-bel-yew-LAIR-ee-a ka-li-FOR-ni-ka
Bigberry Manzanita
Mayfair Ranch, Catamount and Longwall Canyon Trails
Rancho Cañada del Oro Open Space Preserve
This bush or small tree has distinctive reddish brown bark, which is smooth and peeling. The tree is in bloom now with clusters of small white flowers shaped like temple bells. Where manzanita stands are thick, the blossoms falling on the trail look almost like snow.
Manzanita attracts butterflies and bees and the blooms are a nectar source for hummingbirds. Browsing animals like deer will eat the foliage.
Native Americans relied on the manzanita berries as a source for food and beverages. They also used the wood to make pipes and tools and for hot, long-burning fires. Infusions of leaves had many medicinal uses.Scientific name: Arctostaphylos glauca
How to say it: ark-toe-STAF-ih-los GLAW-ka
Oak Trees
Widespread
Rancho Cañada del Oro Open Space Preserve
California has a number of native oak trees including, from left to right, blue oak, valley oak and coast live oak. Each produces distinctive acorns in the fall that play an important part in the life of a woodland community.
Blue oaks are widely distributed in the valleys and lower slopes of the Coast Ranges. These deciduous trees are often found in open savannas and grasslands. Their acorns are palatable to livestock and wildlife, forming an important food source for black-tailed deer, game birds, song birds and rodents.
The valley oak is also deciduous and can grow to be 70 feet tall. As with other oaks, Native Americans found many uses for its acorns, which mature in one year. Besides being ground into meal to make bread, biscuits, soup and mush, the acorns had a variety of medicinal uses.
The coast live oak is everygreen, with prickly leaves that often curl under, especially in response to stressors like drought. The tree provides wintering grounds for dozens of bird species and shelter for cavity-nesting birds. The acorns are a diet staple for black-tailed deer, acorn woodpeckers, yellow-billed magpies and scrub jays.
Along with ground squirrels, scrub jays give back for what they take: their nut-caching behavior and a small measure of forgetfulness ensure that the 5 percent of acorns they bury and don't dig up help the species regenerate.
Scientific Name: Quercus douglasii (blue)
How to say it: KWER-kus DUG-las-ee-eye
Scientific Name: Quercus lobata (valley)
How to say it: KWER-kus lo-BAY-ta
Scientific Name: Quercus agrifolia (coast live)
How to say it: KWER-kus ag-ri-FO-lee-a
Plant Communities
All plants live among other plants. Many factors determine how they group themselves. Elements like soil, water availability, slope, and elevation will draw some plants together and exclude others. Interactions among plant species and among vegetation and wildlife also play a part.
Plant communities often have soft edges where species overlap. And they change through time. Disturbances like fire and flooding can cause sudden, large alterations. A gradual evolution from one set of plants to another, called succession, can take decades or centuries to accomplish the same result.
With all the issues to consider, scientists have worked on defining plant associations for years. There are currently several naming systems that emphasize different concepts within the hierarchy of information about plants and plant relationships.
Our purpose here is descriptive, rather than analytical. We use broad terms to describe plant communities as they might appear to the interested visitor on OSA lands. The vegetation groupings most often encountered along the trail are chaparral, oak woodland, grassland, riparian, and serpentine grassland.
Composed mostly of woody shrubs and small trees, chaparral is primarily a California landscape. Climate – hot dry summers and mild winters with little rain – is the largest influence on this community. Species that can adapt to drought and occasional fire thrive here.
The plants that make up a chaparral community may change from place to place, but the look is much the same: dense, low-growing evergreen bushes (often called brush or scrub) with little space for understory plants.
Reducing evaporation is key to surviving the intense summer heat of inland hillsides and mountain slopes where most chaparral grows. Plants have adapted by developing leaves that are small, thick and leathery. Some have waxy coatings or recessed water-releasing pores. Others align their leaves vertically to limit sun exposure.
They also have evolved fire-survival strategies. Many chaparral natives have deep root systems and will sprout new growth from the crown soon after fire destroys existing wood. Some species have seeds that lie dormant in the soil for years and germinate only after a fire.
Plants often found in chaparral communities include chamise, many species of manzanita and mountain lilac, buckwheat, scrub oak, coffeeberry and toyon.
Oak Woodland
Several oak species grow on Authority lands, including live oak, blue oak and valley oak. The trees tend to follow an open pattern of distribution, with crowns touching but rarely overlapping. This spacing is implied in the use of the term woodland rather than forest.
The openness of oak woodland communities encourages several layers of associated species. Companion trees may include California bay, buckeye, madrone and California walnut. Common understory plants are blackberry, poison oak, blue elderberry, and some shrubs also found in chaparral, such as toyon and manzanita. On the ground, look for California poppies, lupine, miner’s lettuce and a variety of grasses.
Oak trees share some important characteristics that influence the plant communities clustered around them. A dual root system with a deep tap root and several layers of feeder roots helps draw moisture to the surface and is a boon to other plants.
Leaf litter accumulates from year to year, building a mulch that conserves moisture. It also provides a rich habitat for microorganisms that convert the inert matter to useful nutrients.
The abundant production of acorns attracts more wildlife to oak woodland communities than any other. Hundreds of bird, mammal, reptile and insect species form an intricate web of life, multiplying the food sources and enriching the plant environment.
Grassland
California grasslands are perhaps the plant community most impacted by European settlement. The introduction of large grazing animals and imported feed set the stage for a transformation from perennial native bunch grasses to annual pasture grasses.
The natives, like purple needlegrass, adapt to high summer temperatures and limited rainfall by spreading across the landscape in clumps with open land among them. They also have extremely deep roots to draw on water reserves in the dry season. Through a conservative relationship to available water they are able to maintain a long-term growth strategy. Some individual native bunch-grass plants live for hundreds of years.
Annual grasses, by contrast, tell their whole story in one season. They put multiple shallow roots into the top few inches of spring-moist soil, grow like crazy (which cows appreciate), convert all their energy into copious seeds and then die, leaving behind a multitude of offspring to repeat the whole greedy cycle the following year.
Today most grasslands are dominated by the annuals: wild oats, ripgut brome, foxtail barley, ryegrass and others. The grasses may grow in open meadows or as the ground cover in woodlands. Creating openings for the re-establishment of native grasses and the small broad-leaved plants that grow with them, called forbs, is a high priority for the Open Space Authority.
Riparian
Plants that grow along creeks and rivers (that’s what riparian means) are different in many respects from those that manage without a permanent source of water. Most noticeable are the tallest and largest trees, which lose their leaves in winter. The leaves themselves – large, soft and often broadly exposed to the sun – attest to the milder riparian conditions.
The leaf drop of these sycamores, cottonwoods and alders increases the winter sun available to a second tier of riparian plants. Younger willows, mulefat, blackberry, poison oak and other shrubs and vines often create a dense wall of foliage along creek and river banks. Sedges, rushes and cattails at the water’s edge add another habitat dimension.
Nonetheless, it’s the water itself that defines the environment. Variations in flow from drought to flood can drastically rearrange the structure of the water course. Despite fluctuations, however, the composition of the riparian plant community remains much the same, with key species returning even after massive floods.
It’s estimated that 50% of California’s birds, 40% of mammals and reptiles and 80% of amphibians in a given area will spend at least some part of their lives in a riparian environment. Many species of insects including dragonflies, beetles, butterflies and, of course, mosquitoes also thrive in this space where aquatic and land-based resources meet.
Serpentine Grassland
The defining factor of the serpentine grassland community is the soil. Serpentinite arises from the earth’s mantle along fault zones. Soils derived from the rock are rich in magnesium, low in calcium and include heavy metals such as chromium, nickel, and iron.
Nitrogen, potassium, and phosphorus (primary plant nutrients) may be scarce or absent. The soil, being shallow and rocky, holds water poorly and discourages deep root development. It also tends to erode easily.
This is not a welcoming environment. The influx of nonnative species that came to California along with European settlement couldn’t get much of a foothold. Areas of serpentine soils became a refuge for native plants that had adapted to the difficult conditions over many centuries.
Today serpentine soils cover less than 1.5% of California’s total area but support an estimated 10% of the state’s native plants. A number of special-status plants, including Tiburon paintbrush, Santa Clara Valley dudleya, Mount Hamilton thistle, most beautiful jewelflower and dwarf plantain, host plant of the endangered bay checkerspot butterfly, are found there.
Serpentine grasslands are known for their spectacular arrays of spring wildflowers. Multitudes of cream cups, goldfields, and California poppies, interlaced with popcorn flower, owl’s clover, morning glories and many others, paint the hillsides in brilliant color.