It is monoecious with separate male and female flowers on the same plant. The trunk is dark-red brown (not that you can see it hidden by all the foliage in the photos). The sub-species most used in British forestry is ssp. latifolia which has longer leaves (mostly over 6cm long) (whereas ssp. contorata - named after the twisted nature of the cones in the cone - usually has leaves less than 6cm long. Ssp. latifolia is also taller and less bushy than is ssp. contorta.
Easily confused with : several other subspecies of Pinus contorta, namely
Shore Pine (Pinus contorta ssp. contorta) and
Sierra Lodgepole Pine (Pinus contorta ssp. murrayana)
When the leaves are crushed it smells very aromatic with a mixture of MonoTerpenes and Sesquiterpenes. The terpenes present in the tree resin belong to three groups of terpenes: those with the
pinene skeletons, those with mono-cyclic or acyclic frames, and those which are Sesquiterpenes.
Identified in the resin are:
Limonene (2.4%), Sabinene (2.1%),
α-phellandrene (0.7%) and the aliphatic hydrocarbon heptane. Further terpenes are produced by the tree in response to attack by insects or pathogens as a defence mechanism.
Limonene is a cyclic
monoterpene which has a strong smell of lemons and is indeed contained within lemon peel along with a few other MonoTerpenes. Limonene is chiral, having two mirror image forms, lemons containing the (+)-limonene (D-limonene) enantiomer which is dextro-rotatory, rotating the plane of polarised light. Limonene is also present in Oranges, Common Juniper, Spear Mint, Monkey-Puzzle, Man Orchid, Chinese Quince, Sage, Golden Samphire, Rock Samphire and Yarrow amongst many other plants. It degrades quickly in the presence of
Ozone gas (O3) which is present in the air at parts per million concentrations and is produced by ultraviolet light acting on Nitrogen Dioxide pollutants near ground level. This is bad news for Limonene is very likely a messenger and signalling molecule broadcast to pollinators to attract their attention and probably interpretated by other plants for reasons as yet unknown. Even just a few ppm of Ozone will degrade the Limonene into a plethora of other radicals and moieties (1200 components have been experimentally detected) before it travels a few metres from the plants.
α-Pellandrene is a double-bond isomer of β-Phellandrene and is also found in Eucalyptus phellandra (which is now called Eucalyptus radiata). It has a peppery-minty smell slightly reminiscent of citrus fruit.
JASMONATE PLANT HORMONES (AUXINS)
Jasmonic Acid, and its metabolites, is a plant hormone and is derived from
Linolenic Acid. It plays roles in regulating plant development and growth, including growth inhibition, senescence, tendril coiling (but obviously not in Lodgepole Pines), seed germination, flower development, flower form, flowering time, flower opening, the number of open flowers, and leaf fall. It also has a hand in tuber formation of potatoes, yams and onions.
It also plays a role in the wounding response and systemic acquired resistance. It acts as a defence chemical against insects, interfering with their digestive processes.
Jasmonic Acid can be converted into the ester Methyl Jasmonate within the plant, which plays similar roles in plant defence as Jasmonic Acid. Plants produce both chemicals in response to stress or damage. Methyl Jasmonate also signals to remoter parts of the plant (via propagation through the air) forearming them against similar damage or attack, so that they are prepared. But Methyl Jasmonate is a gas which is not very active in plants, but as a gas is able to waft over to nearby plants whereupon it diffuses into the pores of the leaves of nearby un-damaged plants, where, acted upon by water, it gets converted into the water-soluble Jasmonic Acid. The Jasmonic Acid then attaches itself to specific receptors in cells triggering the leafs defence mechanism.
Methyl Jasmonate can also induce the formation of
Ethylene, H2C=CH2, is a gas and
plant hormone that enhances the ripening of nearby fruits.
See Fungal Attack and Resistance.
DiMethylPropane) is an alkane hydrocarbon produced within pine cones. It is gaseous and utilised by the trees as a pesticide against rodents, such as squirrels, who are prone to remove and bury the cones. It is also manufactured commercially for use in products to kill rats and fleas. Isomeric with both
TetraMethylMethane is an extremely inflammable gas. However, unlike its isomers, it is a gas at normal temperatures and pressures (NTP) with melting point of about 9C, whereas pentane (b.p. 36C) and isopentane (b.p. 28C) are both liquids. However, Neopentane can liquefy on cold days when the temperature drops below 9C.