Valley Oak
Encyclopedia
Quercus lobata, commonly called the Valley oak, grows into the largest of North American oaks. It is endemic to California
, growing in the interior valleys and foothills. Mature specimens may attain an age of up to 600 years. This deciduous
oak requires year-round access to groundwater
.
Its thick, ridged bark is characteristic and evokes alligator
hide. The Valley oak's deeply lobed leaves assist in identification.
Typically, leaves are five to ten centimeters in length and are roundly and deeply lobed. The leaf width is approximately one half its length. Each leaf is matte green with an underneath pale green appearance; moreover, the leaf is covered with abundant soft fuzz, yielding an almost velvety feeling. When a fresh leaf is rubbed or broken, an aromatic scent is exuded, evoking a forest odor
. The wood is a dull brown approaching yellow, and it has not been used extensively for milling.
Over most of the range, acorns fall in October. A variety of mammals and bird
s eat them, including the Acorn Woodpecker
, Western Scrub Jay
, Yellow-billed Magpie
, and California ground squirrel
. The acorns are also attacked by bruchid beetles, but can survive moderate levels of infestation. Surviving acorns all germinate in their first winter, and none remain by mid-winter. The acorns are medium to dark brown and range from two to three centimeters in length. The caps have deep stippling and are found most often as singlets, but occasionally as doublets.
Globular gall
s up to several cm. in diameter are frequently attached to twigs of mature specimens of Valley Oak. These house the larval stage of small indigenous wasp
s Andricus
californicus. A related wasp species, A. kingi, produces small galls shaped like Hershey's kisses on leaf surfaces. The valley oak is the only known food plant of Chionodes petalumensis
caterpillar
s.
Like many oaks, Valley Oaks can tolerate wild fires. Although smaller individuals may be top-killed, most resprout from the root crown
s. Commonly associated trees are Coast live oak
, Interior live oak
, Blue oak
, Black walnut
, California Sycamore
and Digger pine.
The Valley oak is widely distributed in: the California Central Valley; many smaller valleys such as the San Fernando Valley
(original Spanish place-name from oak savannah
), Conejo Valley
, and Santa Ynez Valley
; the Inner Coast Ranges
south of the Eel River
; and the Transverse Ranges
from the Tehachapi Mountains
to the Simi Hills
, Santa Susana Mountains
. It is also present on Santa Cruz Island
and Catalina Island
in the Pacific Ocean
. Some of the most picturesque stands are found in Sonoma Valley
, Round Valley in Mendocino County and the southern Salinas Valley
near the up-river reaches of the Salinas River
.
evolution
ary lineage, which is officially known as the subgenus
Lepidobalanus. This subgenus comprises numerous oaks from California and elsewhere, which species share similar leaves, acorn
s, bark and wood pulp
. Early settlers used a variety of common names for the Valley oak including: White oak, bottom oak, swamp oak, water oak and mush oak. The Spaniards, because the tree looked like the white oaks in Europe, called the tree "roble".
In 1792, the English explorer George Vancouver
noted on his expedition through the Santa Clara Valley
, after seeing an expanse of Valley oaks: "For about twenty miles it could only be compared to a park which had originally been closely planted with the true old English oak; the underwood, that had probably attended its early growth, had the appearance of having been cleared away and left the stately lords of the forest in complete possession of the soil which was covered with luxuriant foliage."
In the year 1861, William Henry Brewer
, the chief botanist for the first California Geological Survey
wrote of the Valley oaks that he saw in Monterey County: "First I passed through a wild canyon, then over hills covered with oats, with here and there trees--oaks and pines. Some of these oaks were noble ones indeed. How I wish one stood in our yard at home....I measured one [Valley Oak] with wide spreading and cragged branches, that was 26.5 feet in circumference. Another had a diameter of over six feet, and the branches spread over 75 feet each way. I lay beneath its shade a little while before going on."
The Hooker Oak
of Chico, California
, was once the largest known Valley Oak. When it fell on May 1, 1977, it was nearly a hundred feet tall (30 m) and 29 feet (8.8 m) in circumference eight feet (2.4 m) from the ground.
The Tragedy Oak in Hanford, California
, was at the same place where the historic Mussel Slough Tragedy
gun fight happened in 1880. Six victims of the shooting were carried to the porch of the Brewer house, which was shaded by a tall oak tree. The tree became famously known as the Tragedy Oak. Sadly the tree fell down in a storm in 1995. A part of its trunk was donated by the Warmerdam family, that then owned the land that it grew on, to a nearby school called Pioneer Elementary School.
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
, growing in the interior valleys and foothills. Mature specimens may attain an age of up to 600 years. This deciduous
Deciduous
Deciduous means "falling off at maturity" or "tending to fall off", and is typically used in reference to trees or shrubs that lose their leaves seasonally, and to the shedding of other plant structures such as petals after flowering or fruit when ripe...
oak requires year-round access to groundwater
Groundwater
Groundwater is water located beneath the ground surface in soil pore spaces and in the fractures of rock formations. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in rock...
.
Its thick, ridged bark is characteristic and evokes alligator
Alligator
An alligator is a crocodilian in the genus Alligator of the family Alligatoridae. There are two extant alligator species: the American alligator and the Chinese alligator ....
hide. The Valley oak's deeply lobed leaves assist in identification.
Description and ecology
The sturdy trunk of the Valley oak may exceed two to three meters in diameter and its stature may surpass 30 meters in height. The branches have an irregular, spreading and arching appearance that produce a profound leafless silhouette in the clear winter sky. During Autumn leaves turn a yellow to light orange color but become brown during mid to late fall. In advancing age the branches assume a drooping characteristic. Its pewter-colored rippled bark adds to the attractive aesthetic of this species.Odor
An odor or odour is caused by one or more volatilized chemical compounds, generally at a very low concentration, that humans or other animals perceive by the sense of olfaction. Odors are also commonly called scents, which can refer to both pleasant and unpleasant odors...
. The wood is a dull brown approaching yellow, and it has not been used extensively for milling.
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
s eat them, including the Acorn Woodpecker
Acorn Woodpecker
The Acorn woodpecker is a medium-sized woodpecker, 21 cm long with an average weight of 85 g.-Description:...
, Western Scrub Jay
Western Scrub Jay
The Western Scrub-Jay , is a species of scrub-jay native to western North America. It ranges from southern Washington to central Texas and central Mexico. It comprises three distinct subspecies groups, all of which may be separate species...
, Yellow-billed Magpie
Yellow-billed Magpie
The Yellow-billed Magpie, Pica nuttalli, is a large bird in the crow family found only in California. It inhabits the Central Valley and the adjacent chaparral foothills and mountains...
, and California ground squirrel
California Ground Squirrel
The California ground squirrel , is a common and easily observed ground squirrel of the western United States and the Baja California peninsula; it is common in Oregon and California and its range has relatively recently extended into Washington and northwestern Nevada...
. The acorns are also attacked by bruchid beetles, but can survive moderate levels of infestation. Surviving acorns all germinate in their first winter, and none remain by mid-winter. The acorns are medium to dark brown and range from two to three centimeters in length. The caps have deep stippling and are found most often as singlets, but occasionally as doublets.
Globular gall
Gall
Galls or cecidia are outgrowths on the surface of lifeforms caused by invasion by other lifeforms, such as parasites or bacterial infection. Plant galls are abnormal outgrowths of plant tissues and can be caused by various parasites, from fungi and bacteria, to insects and mites...
s up to several cm. in diameter are frequently attached to twigs of mature specimens of Valley Oak. These house the larval stage of small indigenous wasp
Wasp
The term wasp is typically defined as any insect of the order Hymenoptera and suborder Apocrita that is neither a bee nor an ant. Almost every pest insect species has at least one wasp species that preys upon it or parasitizes it, making wasps critically important in natural control of their...
s Andricus
Andricus
Andricus is a genus of gall wasps in the family Cynipidae, comprising the following species:* Andricus assarehi* Andricus atkinsonae* Andricus californicus* Andricus cecconii* Andricus chodjaii* Andricus conificus...
californicus. A related wasp species, A. kingi, produces small galls shaped like Hershey's kisses on leaf surfaces. The valley oak is the only known food plant of Chionodes petalumensis
Chionodes petalumensis
Chionodes petalumensis is a small moth of the family Gelechiidae. It is found in California, and western North America. -Oaks:The Chionodes petalumensis caterpillars feed on oak leaves, including those of the Garry Oak and Valley Oak , of the California oak woodlands in the chaparral and...
caterpillar
Caterpillar
Caterpillars are the larval form of members of the order Lepidoptera . They are mostly herbivorous in food habit, although some species are insectivorous. Caterpillars are voracious feeders and many of them are considered to be pests in agriculture...
s.
Like many oaks, Valley Oaks can tolerate wild fires. Although smaller individuals may be top-killed, most resprout from the root crown
Distribution and habitat
Valley oak tolerates cool wet winters and hot dry summers, but requires abundant water. It is most abundant in rich deep soils of valley floors below 600 meters in elevation. Valley oak is found in dense riparian forests, open foothill woodlands and valley savannaSavanna
A savanna, or savannah, is a grassland ecosystem characterized by the trees being sufficiently small or widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to support an unbroken herbaceous layer consisting primarily of C4 grasses.Some...
s. Commonly associated trees are Coast live oak
Coast Live Oak
Quercus agrifolia, the Coast Live Oak, is an evergreen oak , native to the California Floristic Province. It grows west of the Sierra Nevada from Mendocino County, California, south to northern Baja California in Mexico. It is classified in the red oak section Quercus agrifolia, the Coast Live Oak,...
, Interior live oak
Interior Live Oak
Quercus wislizeni, known by the common names Interior Live Oak, and Sierra Live Oak, is an evergeen oak, highly variable and often shrubby, found in areas of California in the United States. It also occurs south into northern Baja California in Mexico...
, Blue oak
Blue Oak
Quercus douglasii, the Blue Oak, is an oak in the white oak section of the genus, Quercus sect. Quercus. It is endemic to California and is found in foothills surrounding the Central Valley of California and certain locations in the California Coast Ranges, USA...
, Black walnut
Black Walnut
Juglans nigra, the Eastern Black walnut, is a species of flowering tree in the hickory family, Juglandaceae, that is native to eastern North America. It grows mostly in riparian zones, from southern Ontario, west to southeast South Dakota, south to Georgia, northern Florida and southwest to central...
, California Sycamore
California Sycamore
Platanus racemosa is a species of sycamore tree known by several common names, including California sycamore, Western sycamore, California plane tree, and in Spanish Aliso...
and Digger pine.
The Valley oak is widely distributed in: the California Central Valley; many smaller valleys such as the San Fernando Valley
San Fernando Valley
The San Fernando Valley is an urbanized valley located in the Los Angeles metropolitan area of southern California, United States, defined by the dramatic mountains of the Transverse Ranges circling it...
(original Spanish place-name from oak savannah
California oak woodland
California oak woodland is a plant community found throughout the California chaparral and woodlands ecoregion of California in the United States and northwestern Baja California in Mexico...
), Conejo Valley
Conejo Valley
The Conejo Valley is a region spanning both southeastern Ventura County and northwestern Los Angeles County in Southern California, United States...
, and Santa Ynez Valley
Santa Ynez Valley
The Santa Ynez Valley is located in Santa Barbara County, California, between the Santa Ynez Mountains to the south and the San Rafael Mountains to the north. The Santa Ynez River flows through the valley from east to west. The Santa Ynez Valley is separated from the Los Alamos Valley, to the...
; the Inner Coast Ranges
Inner Coast Ranges
The Inner Coast Ranges are an extensive mountain range within California in the USA. In Northern California the ranges can be characterized as a mountainous landform from near Anderson, California south along the east slope of the North Coast Ranges, around the south end of the High North Coast...
south of the Eel River
Eel River (California)
The Eel River is a major river system of the northern Pacific coast of the U.S. state of California. Approximately 200 miles long, it drains a rugged area in the California Coast Ranges between the Sacramento Valley and the ocean. For most of its course, the river flows northwest, parallel to the...
; and the Transverse Ranges
Transverse Ranges
The Transverse Ranges are a group of mountain ranges of southern California, in the Pacific Coast Ranges physiographic region that runs along the Pacific coast from Alaska to Mexico in North America. The Transverse Ranges begin at the southern end of the California Coast Ranges and lie between...
from the Tehachapi Mountains
Tehachapi Mountains
The Tehachapi Mountains , regionally also called The Tehachapis, are a mountain range in the Transverse Ranges system of California in the Western United States...
to the Simi Hills
Simi Hills
The Simi Hills are a low rocky mountain range of the Transverse Ranges, located in eastern Ventura County and western Los Angeles County, of southern California, United States.-Geography:...
, Santa Susana Mountains
Santa Susana Mountains
The Santa Susana Mountains are a transverse range of mountains in southern California, north of the city of Los Angeles, in the United States. The range runs east-west separating the San Fernando Valley and Simi Valley on its south, from Santa Clara River Valley to the north, and Santa Clarita...
. It is also present on Santa Cruz Island
Santa Cruz Island
Santa Cruz Island was the largest privately owned island off the continental United States, but is currently part-owned by the National Park service . The island, located off the coast of California, is long and from wide...
and Catalina Island
Santa Catalina Island, California
Santa Catalina Island, often called Catalina Island, or just Catalina, is a rocky island off the coast of the U.S. state of California. The island is long and across at its greatest width. The island is located about south-southwest of Los Angeles, California. The highest point on the island is...
in the Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
. Some of the most picturesque stands are found in Sonoma Valley
Sonoma Valley
Sonoma Valley is the birthplace of the California wine industry and often called The Valley of the Moon. Sonoma Valley is home to some of the earliest vineyards and wineries in the state, some of which survived the phylloxera epidemic of the 1870s and the impact of Prohibition...
, Round Valley in Mendocino County and the southern Salinas Valley
Salinas Valley
The Salinas Valley lies south of San Francisco, California.The word "salina" is spanish for salt marsh, salt lake or salt pan.-Geography:The Salinas Valley runs approximately south-east from Salinas towards King City. The valley lends its name to the geologic province in which it's located, the...
near the up-river reaches of the Salinas River
Salinas River (California)
The Salinas River is the largest river of the central coast of California, running and draining 4,160 square miles. It flows north-northwest and drains the Salinas Valley that slices through the Coast Range south from Monterey Bay...
.
Taxonomy
Valley oak is of the White oakWhite oak
Quercus alba, the white oak, is one of the pre-eminent hardwoods of eastern North America. It is a long-lived oak of the Fagaceae family, native to eastern North America and found from southern Quebec west to eastern Minnesota and south to northern Florida and eastern Texas. Specimens have been...
evolution
Evolution
Evolution is any change across successive generations in the heritable characteristics of biological populations. Evolutionary processes give rise to diversity at every level of biological organisation, including species, individual organisms and molecules such as DNA and proteins.Life on Earth...
ary lineage, which is officially known as the subgenus
Subgenus
In biology, a subgenus is a taxonomic rank directly below genus.In zoology, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the generic name and the specific epithet: e.g. the Tiger Cowry of the Indo-Pacific, Cypraea tigris Linnaeus, which...
Lepidobalanus. This subgenus comprises numerous oaks from California and elsewhere, which species share similar leaves, acorn
Acorn
The acorn, or oak nut, is the nut of the oaks and their close relatives . It usually contains a single seed , enclosed in a tough, leathery shell, and borne in a cup-shaped cupule. Acorns vary from 1–6 cm long and 0.8–4 cm broad...
s, bark and wood pulp
Wood pulp
Pulp is a lignocellulosic fibrous material prepared by chemically or mechanically separating cellulose fibres from wood, fibre crops or waste paper. Wood pulp is the most common raw material in papermaking.-History:...
. Early settlers used a variety of common names for the Valley oak including: White oak, bottom oak, swamp oak, water oak and mush oak. The Spaniards, because the tree looked like the white oaks in Europe, called the tree "roble".
Historical accounts
(This needs references; in fact the entire article is largely devoid of references)In 1792, the English explorer George Vancouver
George Vancouver
Captain George Vancouver RN was an English officer of the British Royal Navy, best known for his 1791-95 expedition, which explored and charted North America's northwestern Pacific Coast regions, including the coasts of contemporary Alaska, British Columbia, Washington and Oregon...
noted on his expedition through the Santa Clara Valley
Santa Clara Valley
The Santa Clara Valley is a valley just south of the San Francisco Bay in Northern California in the United States. Much of Santa Clara County and its county seat, San José, are in the Santa Clara Valley. The valley was originally known as the Valley of Heart’s Delight for its high concentration...
, after seeing an expanse of Valley oaks: "For about twenty miles it could only be compared to a park which had originally been closely planted with the true old English oak; the underwood, that had probably attended its early growth, had the appearance of having been cleared away and left the stately lords of the forest in complete possession of the soil which was covered with luxuriant foliage."
In the year 1861, William Henry Brewer
William Henry Brewer
William Henry Brewer was an American botanist. He worked on the first California Geological Survey and was the first Chair of Agriculture at Yale University's Sheffield Scientific School....
, the chief botanist for the first California Geological Survey
California Geological Survey
Although it was not until 1880 that the California State Mining Bureau, predecessor to the California Geological Survey, was established, the "roots" of California's state geological survey date to an earlier time...
wrote of the Valley oaks that he saw in Monterey County: "First I passed through a wild canyon, then over hills covered with oats, with here and there trees--oaks and pines. Some of these oaks were noble ones indeed. How I wish one stood in our yard at home....I measured one [Valley Oak] with wide spreading and cragged branches, that was 26.5 feet in circumference. Another had a diameter of over six feet, and the branches spread over 75 feet each way. I lay beneath its shade a little while before going on."
The Hooker Oak
Hooker Oak
Hooker Oak was a large valley oak tree in Chico, California. It was named after English botanist and Director of the Royal Botanical Gardens, Sir Joseph Dalton Hooker by Annie Bidwell in 1887...
of Chico, California
Chico, California
Chico is the most populous city in Butte County, California, United States. The population was 86,187 at the 2010 census, up from 59,954 at the time of the 2000 census...
, was once the largest known Valley Oak. When it fell on May 1, 1977, it was nearly a hundred feet tall (30 m) and 29 feet (8.8 m) in circumference eight feet (2.4 m) from the ground.
The Tragedy Oak in Hanford, California
Hanford, California
Hanford is an important commercial and cultural center in the south central San Joaquin Valley and is the county seat of Kings County, California. It is the principal city of the Hanford-Corcoran, California Metropolitan Statistical Area , which encompasses all of Kings County, including the cities...
, was at the same place where the historic Mussel Slough Tragedy
Mussel Slough Tragedy
The Mussel Slough Tragedy was a dispute over land titles between settlers and the Southern Pacific Railroad that took place on May 11, 1880, on a farm located northwest of Hanford, California, in the central San Joaquin Valley, leaving seven people dead. Frank Norris' 1901 novel, The Octopus: A...
gun fight happened in 1880. Six victims of the shooting were carried to the porch of the Brewer house, which was shaded by a tall oak tree. The tree became famously known as the Tragedy Oak. Sadly the tree fell down in a storm in 1995. A part of its trunk was donated by the Warmerdam family, that then owned the land that it grew on, to a nearby school called Pioneer Elementary School.
See also
- California oak woodlandCalifornia oak woodlandCalifornia oak woodland is a plant community found throughout the California chaparral and woodlands ecoregion of California in the United States and northwestern Baja California in Mexico...
- List of Quercus species
- California chaparral and woodlandsCalifornia chaparral and woodlandsThe California chaparral and woodlands is a terrestrial ecoregion of lower northern, central, and southern California and northwestern Baja California , located on the west coast of North America...
- California native plantsCalifornia native plantsCalifornia native plants are plants that existed in California prior to the arrival of European explorers and colonists in the late 18th century...