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 state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington, while the Snake River delineates much of its eastern boundary with Idaho. T ...
to
Baja California
Baja California (; 'Lower California'), officially the Free and Sovereign State of Baja California ( es, Estado Libre y Soberano de Baja California), is a state in Mexico. It is the northernmost and westernmost of the 32 federal entities of Mex ...
with the greatest concentration in northern
California
California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...
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 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 are in fascicles of three, needle-like, yellow-green, twisted, and long. The
cone
A cone is a three-dimensional geometric shape that tapers smoothly from a flat base (frequently, though not necessarily, circular) to a point called the apex or vertex.
A cone is formed by a set of line segments, half-lines, or lines con ...
s are resin-sealed and irregularly shaped,
long and clustered in
whorls
A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs).
Whorls in nature
File:Photograph and axial plane floral ...
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. It is always on or near the coast.
In San Luis Obispo ...
''), 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 ( Guadalupe Island and Cedros island). It is an evergreen conifer in the ...
'').
In the western foothills of the
Sierra Nevada, 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 (and found only in) 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 domina ...
'').
[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
The Coulter pine or big-cone pine, ''Pinus coulteri'', is a native of the coastal mountains of Southern California in the United States and northern Baja California in Mexico. Isolated groves are found as far north as Clearlake, California on the ...
* '' 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 the Southwestern United States
Trees of the Northwestern United States
Least concern flora of the United States
Trees of Baja California