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Juniperus occidentalis

Juniperus occidentalis

Overview
Juniperus occidentalis (Western Juniper and Sierra Juniper) is a shrub
Shrub
A shrub or bush is a horticultural rather than strictly botanical category of woody plant, distinguished from a tree by its multiple stems and lower height, usually less than 5-6 m tall. A large number of plants can be either shrubs or trees, depending on the growing conditions they experience...

 or tree
Tree
A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...

 native to the western United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, growing in mountain
Mountain
A mountain is a large landform that stretches above the surrounding land in a limited area usually in the form of a peak. A mountain is generally steeper than a hill. The adjective montane is used to describe mountainous areas and things associated with them...

s at altitudes of 800-3,000 m (rarely down to 100 m).



The shoots are of moderate thickness among juniper
Juniper
Junipers are coniferous plants in the genus Juniperus of the cypress family Cupressaceae. Depending on taxonomic viewpoint, there are between 50-67 species of juniper, widely distributed throughout the northern hemisphere, from the Arctic, south to tropical Africa in the Old World, and to the...

s, 1-1.6 mm diameter. The leaves
Leaf
In botany, a leaf is an above-ground plant organ specialized for photosynthesis. For this purpose, a leaf is typically flat and thin. There is continued debate about whether the flatness of leaves evolved to expose the chloroplasts to more light or to increase the absorption of carbon dioxide. In...

 are arranged in opposite decussate pairs or whorls of three; the adult leaves are scale-like, 1-2 mm long (to 5 mm on lead shoots) and 1-1.5 mm broad.
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Encyclopedia
Juniperus occidentalis (Western Juniper and Sierra Juniper) is a shrub
Shrub
A shrub or bush is a horticultural rather than strictly botanical category of woody plant, distinguished from a tree by its multiple stems and lower height, usually less than 5-6 m tall. A large number of plants can be either shrubs or trees, depending on the growing conditions they experience...

 or tree
Tree
A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...

 native to the western United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, growing in mountain
Mountain
A mountain is a large landform that stretches above the surrounding land in a limited area usually in the form of a peak. A mountain is generally steeper than a hill. The adjective montane is used to describe mountainous areas and things associated with them...

s at altitudes of 800-3,000 m (rarely down to 100 m).



The shoots are of moderate thickness among juniper
Juniper
Junipers are coniferous plants in the genus Juniperus of the cypress family Cupressaceae. Depending on taxonomic viewpoint, there are between 50-67 species of juniper, widely distributed throughout the northern hemisphere, from the Arctic, south to tropical Africa in the Old World, and to the...

s, 1-1.6 mm diameter. The leaves
Leaf
In botany, a leaf is an above-ground plant organ specialized for photosynthesis. For this purpose, a leaf is typically flat and thin. There is continued debate about whether the flatness of leaves evolved to expose the chloroplasts to more light or to increase the absorption of carbon dioxide. In...

 are arranged in opposite decussate pairs or whorls of three; the adult leaves are scale-like, 1-2 mm long (to 5 mm on lead shoots) and 1-1.5 mm broad. The juvenile leaves (on young seedlings only) are needle-like, 5-10 mm long. The cones
Conifer cone
A cone is an organ on plants in the division Pinophyta that contains the reproductive structures. The familiar woody cone is the female cone, which produces seeds. The male cones, which produce pollen, are usually herbaceous and much less conspicuous even at full maturity...

 are berry-like, 5-10 mm in diameter, blue-brown with a whitish waxy bloom, and contain one to three seed
Seed
A seed , referred to as a kernel in some plants, is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...

s; they are mature in about 18 months. The male cones are 2-4 mm long, and shed their pollen in early spring.

It usually occurs on dry, rocky sites where there is less competition from larger species like Ponderosa Pine
Ponderosa Pine
Ponderosa Pine , sometimes called Bull Pine or Western Yellow Pine, is a widespread and variable pine native to western North America. It was first described by David Douglas in 1826, from eastern Washington near present-day Spokane. It is a dominant tree in the Kuchler plant association Ponderosa...

 and Coast Douglas-fir
Coast Douglas-fir
The Coast Douglas-fir , a variety of Douglas-fir, is an evergreen conifer native to the coastal regions of western North America, from west-central British Columbia, Canada southward to central California, United States. In Oregon and Washington its range is continuous from the Cascades crest west...

. Hybrids with Juniperus osteosperma
Juniperus osteosperma
Juniperus osteosperma is a shrub or small tree reaching 3-6 m tall. It is native to the southwestern United States, in Utah, Nevada, Arizona, western New Mexico, western Colorado, Wyoming, southern Montana, southern Idaho and eastern California...

are occasionally found.

The cones are an important food for several bird
Bird
Birds are winged, bipedal, endothermic , vertebrate animals that lay eggs. There are around 10,000 living species, making them the most numerous tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Birds range in size from the Bee Hummingbird to the ...

s, including American Robin
American Robin
The American Robin is a migratory songbird of the thrush family. It is named after the European Robin because of the male's bright red breast, though the two species are not closely related...

, Phainopepla
Phainopepla
The Phainopepla is the most northerly representative of the mainly tropical Central American family Ptilogonatidae, the silky flycatchers.-Physical description:...

 and Cedar Waxwing
Cedar Waxwing
The Cedar Waxwing is a member of the family Bombycillidae or waxwing family of passerine birds. It breeds in open wooded areas in North America, principally southern Canada and the northern United States.-Description:...

; these digest the fleshy cone scales and disperse the seeds in their droppings. The plants often bear gall
Gall
Galls or plant galls are abnormal outgrowths of plant tissues and can be caused by various parasites, from fungi and bacteria, to insects and mites. Galls are often highly organised structures and because of this the cause of the gall can often be determined without the actual agent being identified...

s caused by the Juniper Tip Midge Oligotrophus betheli (Bibionomorpha
Bibionomorpha
Bibionomorpha is a infraorder of Nematocera. One of its constituent families, the Anisopodidae, is the presumed sister taxon to the entire suborder Brachycera. Several of the remaining families in the infraorder are former subfamilies of the Mycetophilidae, which has been recently subdivided...

: Cecidomyiidae); these are violet-purple fading to brown, 1-2 cm diameter, with dense modified spreading scale-leaves 6-10 mm long and 2-3 mm broad at the base.

There are two varieties
Variety (biology)
In botanical nomenclature, variety is a taxonomic rank below that of species: As such, it gets a ternary name .A variety will have an appearance distinct from other varieties, but will hybridize freely with those other varieties...

, treated as subspecies
Subspecies
Subspecies in biological classification, is 1) a taxonomic rank subordinate to species, or 2) a taxonomic unit, a taxon in that rank...

 by some botanists:
  • Juniperus occidentalis var. occidentalis Western Juniper. Southeast Washington
    Washington
    Washington is a state in the Pacific Northwest region of the United States. Washington was carved out of the western part of Washington Territory which had been ceded by Britain in 1846 by the Oregon Treaty as settlement of the Oregon Boundary Dispute. It was admitted to the Union as the...

    , eastern and central Oregon
    Oregon
    Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...

    , southwest Idaho
    Idaho
    Idaho is a state in the Pacific Northwest region of the United States of America. The state's largest city and capital is Boise. Residents are called "Idahoans." Idaho was admitted to the Union on 3 July 1890 as the 43rd state....

    , northeastern California
    California
    California is the most populous state in the United States, and the third largest by area. California is the second most populous sub-national entity in the Americas, behind only São Paulo, Brazil...

     and extreme northwest Nevada
    Nevada
    Nevada is a state located in the western region of the United States. The capital is Carson City and the largest city is Las Vegas. The state's nickname is Silver State, due to the large number of silver deposits that were discovered and mined there...

    , north of 40° 30' N latitude, east of the Cascade Range
    Cascade Range
    The Cascade Range is a major mountain range of western North America, extending from southern British Columbia through Washington and Oregon to Northern California. It includes both non-volcanic mountains, such as the North Cascades, and the notable volcanoes known as the High Cascades...

    . A shrub or small tree 4-15 m tall. Exceptionally tall specimens can be found in the John Day area of Oregon well in excess of 26-28 m tall (80-90 feet+) competing for sunlight among Ponderosa Pines at the bottom of some deep side canyons, but on open and barren ground 4-15 m with a bushier growth habit is more common. Cones 7-10 mm diameter. About 50% of plants are monoecious
    Plant sexuality
    Plant sexuality covers the wide variety of sexual reproduction systems found across the plant kingdom. This article describes morphological aspects of sexual reproduction of plants....

     with both sexes on the same plant, 50% dioecious
    Plant sexuality
    Plant sexuality covers the wide variety of sexual reproduction systems found across the plant kingdom. This article describes morphological aspects of sexual reproduction of plants....

    , producing cones of only one sex.
  • Juniperus occidentalis var. australis Sierra Juniper. California
    California
    California is the most populous state in the United States, and the third largest by area. California is the second most populous sub-national entity in the Americas, behind only São Paulo, Brazil...

     and westernmost Nevada
    Nevada
    Nevada is a state located in the western region of the United States. The capital is Carson City and the largest city is Las Vegas. The state's nickname is Silver State, due to the large number of silver deposits that were discovered and mined there...

    , south of 40° 30' N latitude in the Sierra Nevada and San Bernardino Mountains
    San Bernardino Mountains
    The San Bernardino Mountains are a short transverse mountain range north and east of San Bernardino in Southern California in the United States. The mountains run for approximately 60 miles east-west on the southern edge of the Mojave Desert in southwestern San Bernardino County, north of the...

    . A medium-sized tree 12-26 m tall with a stout trunk up to 3 m diameter. Cones 5-9 mm diameter. Most plants dioecious, but about 5-10% are monoecious.


The Bennett Juniper in the Stanislaus National Forest
Stanislaus National Forest
Stanislaus National Forest contains in four counties in the Sierra Nevada Mountains of Northern California. It was established on February 22, 1897, making it one of the oldest national forests. It was named after the Stanislaus River. The Emigrant Wilderness is located entirely within its...

 of California
California
California is the most populous state in the United States, and the third largest by area. California is the second most populous sub-national entity in the Americas, behind only São Paulo, Brazil...

is one of the oldest and largest examples at possibly 3000 years old, with a height of 26 m and a diameter of 3.88 m http://www.conifers.org/cu/ju/australis.htm.