The knobcone pine, ''Pinus attenuata'' (also called ''Pinus tuberculata''), is a tree that grows in mild climates on poor soils. It ranges from the mountains of southern
Oregon
Oregon ( , ) is a U.S. state, state in the Pacific Northwest region of the United States. It is a part of the Western U.S., with the Columbia River delineating much of Oregon's northern boundary with Washington (state), Washington, while t ...
to
Baja California
Baja California, officially the Free and Sovereign State of Baja California, is a state in Mexico. It is the northwesternmost of the 32 federal entities of Mexico. Before becoming a state in 1952, the area was known as the North Territory of B ...
with the greatest concentration in northern
California
California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...
and the Oregon-California border.
Description
Individual specimens can live up to a century.
The crown is usually conical with a straight trunk. It reaches heights of , but can be a shrub on especially poor sites. The
bark
Bark may refer to:
Common meanings
* Bark (botany), an outer layer of a woody plant such as a tree or stick
* Bark (sound), a vocalization of some animals (which is commonly the dog)
Arts and entertainment
* ''Bark'' (Jefferson Airplane album), ...
is thin and smooth, flaky and gray-brown when young, becoming dark
gray-red-brown and shallowly furrowed into flat scaly ridges in age. The twigs are red-brown and often resinous. Its wood is knotty and of little interest for lumber.
The
leaves
A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, ...
are in fascicles of three, needle-like, yellow-green, twisted, and long. The
cone
In geometry, a cone is a three-dimensional figure that tapers smoothly from a flat base (typically a circle) to a point not contained in the base, called the '' apex'' or '' vertex''.
A cone is formed by a set of line segments, half-lines ...
s are resin-sealed and irregularly shaped,
long and clustered in
whorls of three to six on the branches. The scales end in a short stout prickle. Cones can sometimes be found attached to the trunk and larger branches.
Distribution
The knobcone pine can be found growing in the dry, rocky soils of southern Oregon and northern California, between above sea level.
It forms nearly pure stands, preferring to grow where there is no competition.
Ecology
On the coast, the knobcone pine may
hybridize with bishop pine (''
Pinus muricata
''Pinus muricata'', the bishop pine, is a pine with a very restricted range: mostly in California, including several offshore Channel Islands, and a few locations in Baja California, Mexico. Stands of Bishop Pine are also found in Point Reyes Nat ...
''), and Monterey pine (''
Pinus radiata
''Pinus radiata'' ( syn. ''Pinus insignis''), the Monterey pine, insignis pine or radiata pine, is a species of pine native to the Central Coast of California and Mexico (on Guadalupe Island and Cedros island). It is an evergreen conifer in t ...
'').
In the western foothills of the
Sierra Nevada
The Sierra Nevada ( ) is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primari ...
, knobcone pine is often a co-dominant with blue oak (''
Quercus douglasii
''Quercus douglasii'', known as blue oak, is a species of oak endemic to California, common in the Coast Ranges and the foothills of the Sierra Nevada. It is California's most drought-tolerant deciduous oak, and is a dominant species in the b ...
'').
[Hogan, C. Michael (2008)]
''Blue Oak: Quercus douglasii'', GlobalTwitcher.com, ed. Nicklas Stromberg
/ref>
The species is susceptible to fire, but this melts the cone resin, releasing seeds for regrowth.
See also
* Coulter pine
* '' Pinus sabiniana''
References
Further reading
* Bakker, Elna S. (1971). ''An island called California''. University of California press (1972).
External links
*
USDA Plants Profile: ''Pinus attenuata''
Virginia Tech Dendrology – Knobcone Pine
*
{{Taxonbar, from=Q2703208
Pinus
Trees of Northern America
Least concern flora of the United States