''Pinus jeffreyi'', also known as Jeffrey pine, Jeffrey's pine, yellow pine and black pine, is a

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and th ...

pine A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family (biology), family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The World Flora Online created by the Royal Botanic Gardens, Kew and Missouri Botanic ...

tree. It is mainly found in

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 ...

, but also in the westernmost part of

Nevada Nevada ( ; ) is a U.S. state, state in the Western United States, Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. N ...

, southwestern

Oregon Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of it ...

, and northern

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 ...

.Safford, H.D. 2013. Natural Range of Variation (NRV) for yellow pine and mixed conifer forests in the bioregional assessment area, including the Sierra Nevada, southern Cascades, and Modoc and Inyo National Forests. Unpublished report. USDA Forest Service, Pacific Southwest Region, Vallejo, CA

/ref> It is named in honor of its botanist documenter John Jeffrey (botanist), John Jeffrey.

Description

''Pinus jeffreyi'' is a large

coniferous Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single extant class, Pinopsida. All ext ...

evergreen In botany, an evergreen is a plant which has foliage that remains green and functional through more than one growing season. This also pertains to plants that retain their foliage only in warm climates, and contrasts with deciduous plants, whic ...

tree, reaching tall, rarely up to tall, though smaller when growing at or near

tree line The tree line is the edge of the habitat at which trees are capable of growing. It is found at high elevations and high latitudes. Beyond the tree line, trees cannot tolerate the environmental conditions (usually cold temperatures, extreme snow ...

. The

leaves A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, st ...

are needle-like, in bundles of three, stout,

glaucous ''Glaucous'' (, ) is used to describe the pale grey or bluish-green appearance of the surfaces of some plants, as well as in the names of birds, such as the glaucous gull (''Larus hyperboreus''), glaucous-winged gull (''Larus glaucescens''), ...

gray-green, long. The cones are long, dark purple when immature, ripening pale brown, with thinly woody scales bearing a short, sharp inward-pointing barb. The seeds are long, with a large () wing. ''Pinus jeffreyi'' is closely related to ''

Pinus ponderosa ''Pinus ponderosa'', commonly known as the ponderosa pine, bull pine, blackjack pine, western yellow-pine, or filipinus pine is a very large pine tree species of variable habitat native to mountainous regions of western North America. It is the ...

'' (ponderosa pine) and is similar in appearance. One way to distinguish between them is by their cones. Each has barbs at the end of the scales. The sharp ''Pinus jeffreyi'' cone scale barbs point inward, so the cone feels smooth to the palm of one's hand when rubbed down the cone. ''Pinus ponderosa'' cone scale barbs point outward, so feel sharp and prickly to the palm of one's hands. The memory device of 'gentle Jeffrey' and 'prickly ponderosa' can be used to differentiate between the species. Another distinguishing characteristic is that the needles of ''Pinus jeffreyi'' are glaucous, less bright green than those of ''Pinus ponderosa'', and by the stouter, heavier cones with larger seeds and inward-pointing barbs. ''Pinus jeffreyi'' can be somewhat distinguished from ''Pinus ponderosa'' by the relatively smaller scales of reddish-brown bark as compared to the larger plates of orangish ponderosa bark. The scent of ''Pinus jeffreyi'' is variously described as reminiscent of vanilla, lemon, pineapple, violets, apple, and, quite commonly, butterscotch. This scent may be sampled by breaking off a shoot or some needles, or by simply smelling the resin's scent in between the plates of the bark. This scent is related to the very unusual composition of the resin, with the volatile component made up almost entirely of pure

n-heptane Heptane or ''n''-heptane is the straight-chain alkane with the chemical formula H3C(CH2)5CH3 or C7H16. When used as a test fuel component in anti-knock test engines, a 100% heptane fuel is the zero point of the octane rating scale (the 100 poi ...

. The largest ''Pinus jeffreyi'', by trunk volume, is the Eureka Valley Giant, in the

Stanislaus National Forest Stanislaus National Forest is a U.S. National Forest which manages of land in four counties in the Sierra Nevada in Northern California. It was established on February 22, 1897, making it one of the oldest national forests. It was named after th ...

. Its trunk contains of wood, is tall, with a diameter of .

Distribution and habitat

''Pinus jeffreyi'' occurs from southwest

south through much of

(mainly on the eastern side 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 primar ...

), to northern

in Mexico. It is a high-altitude species; in the north of its range, it grows widely at altitude, and at in the south of its range. ''Pinus jeffreyi'' is more stress tolerant than ''Pinus ponderosa''. At higher elevations, on poorer soils, in colder climates, and in dryer climates, ''Pinus jeffreyi'' replaces ''Pinus ponderosa'' as the dominant tree. ''Pinus jeffreyi'' is also tolerant of

serpentine soil Serpentine soil is an uncommon soil type produced by weathered ultramafic rock such as peridotite and its metamorphic derivatives such as serpentinite. More precisely, serpentine soil contains minerals of the serpentine subgroup, especially anti ...

s and is often dominant in these conditions, even on dry sites at fairly low altitudes. Jeffrey pine Siskiyou Wilderness

Ecology

''Pinus jeffreyi'' can hybridize with ''Pinus ponderosa'' and the ''

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 ...

,'' however this occurrence is rare due to the fact that the pines release pollen at different periods of time, and they naturally have difficulty crossing. However, hybrids do occasionally occur.

Uses

''Pinus jeffreyi'' wood is similar to ponderosa pine wood, and is used for the same purposes. Crystallized sap of ''Pinus jeffreyi'' has been eaten as candy. The exceptional purity of

distilled from ''Pinus jeffreyi'' resin led to n-heptane being selected as the zero point on the

octane rating An octane rating, or octane number, is a standard measure of a fuel's ability to withstand compression in an internal combustion engine without detonating. The higher the octane number, the more compression the fuel can withstand before detonatin ...

scale of

petrol Gasoline (; ) or petrol (; ) (see ) is a transparent, petroleum-derived flammable liquid that is used primarily as a fuel in most spark-ignited internal combustion engines (also known as petrol engines). It consists mostly of organic c ...

. As it mainly consists of n-heptane, ''Pinus jeffreyi'' resin is a poor source of

turpentine Turpentine (which is also called spirit of turpentine, oil of turpentine, terebenthene, terebinthine and (colloquially) turps) is a fluid obtained by the distillation of resin harvested from living trees, mainly pines. Mainly used as a special ...

. Before ''Pinus jeffreyi'' was distinguished from ponderosa pine as a distinct species in 1853, resin distillers operating in its range suffered a number of "inexplicable" explosions during distillation, now known to have been caused by the unwitting use of Jeffrey pine resin.

Taxonomy

''Pinus jeffreyi'' is named for its discoverer, Scottish botanist John Jeffrey (botanist), John Jeffrey, who encountered it in 1852 near Mount Shasta. ''Pinus'' is Latin for pine.

References

External links

* * {{Taxonbar, from=Q251370 jeffreyi Trees of Baja California Trees of the Southwestern United States Trees of the Northwestern United States Trees of the United States Flora of California Flora of Oregon Flora of the Sierra Nevada (United States) Natural history of the California Coast Ranges Least concern flora of the United States Plants described in 1853 Taxa named by John Hutton Balfour