Common Name: Jeffrey Pine

General Information

Pinus jeffreyi is an evergreen tree with a rounded to conic crown; it can grow up to 61 metres tall. The usually straight, cylindrical bole can be up to 250cm in diameter[].
The plant is traditionally harvested from the wild for local use as a food and source of materials. It is an important source of timber in its area, where it is often harvested from the wild for its wood - this is used locally and also traded, usually under the name of the closely related species Pinus ponderosa[]. The tree has also been harvested for its oleoresin, distillations of which have been used as an additive to petrol. It is sometimes grown as an ornamental.
Pinus jeffreyi is very widespread and abundant and regenerates well after disturbance events, including logging. A potential threat to play a role in future reduction of subpopulations near urban centres is air pollution. However, no direct links between local die back and air pollution have yet been recorded. The plant is classified as 'Least Concern' in the IUCN Red List of Threatened Species(2013)[].

Known Hazards

The wood, sawdust and resins from various species of pine can cause dermatitis in sensitive people[].

Botanical References

, ,

Range

Western N. America - southern Oregon, California, Nevada, Baja Norte.

Habitat

Usually found in open, mixed conifer forests on dry and exposed slopes, at elevations from 300 - 3,050 metres[, , ]. Found on a variety of soils, but growing best in those that are deep and well-drained[].

Properties

Conservation Status	Least Concern
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Evergreen Tree
Height	25.00 m
Growth Rate	Medium
Pollinators	Wind
Self-fertile	No
Cultivation Status	Ornamental, Wild

Cultivation Details

Pinus jeffreyi is not a very cold-hardy plant, being able to tolerate short periods with temperatures down to around -5 to -10°c when fully dormant[].
Pine species in general require a sunny position if they are to grow well and, whilst the different species have their own soil preferences, most will thrive in a light well-drained sandy or gravelly loam[, ]. Succeeds in most soils[]. The plant can grow on thin soil or even in crevices of bare granite rock in the wild[]. Dislikes poorly drained moorland soils[]. Established plants tolerate drought[].
A very ornamental plant[]. It is often short-lived in Britain but is moderately fast growing with some trees reaching a height of 15 metres in 29 years[].
A long-lived tree in the wild, specimens 500 years old are known[]. It commences bearing seeds when about 10 - 15 years old, though good production does not commence until twice that age[].
Plants are strongly outbreeding, self-fertilized seed usually grows poorly[]. They hybridize freely with other members of this genus[]. Closely related to Pinus ponderosa[], and hybridizes with it in the wild[]. Some of the earlier plantings under this name in Britain have turned out to be Pinus ponderosa[].
The seed cones are 12 - 35cm long. They take two growing seasons to maturie, shedding ther seeds whilst still attached to the tree and falling soon thereafter[, , ].
The resin from broken shoots has a very strong lemon scent[].
Plants in this genus are notably susceptible to honey fungus[].

Edible Uses

Seed - raw or cooked[, ]. Large[]. The oil-rich seed has a resinous flavour and is about 10 - 12mm long[, ].

The crystallised sap has been gathered and eaten like candy[].

A vanillin flavouring is obtained as a by-product of other resins that are released from the pulpwood[].

Medicinal

Oil of turpentine, obtained from the oleo-resin of all pine trees, is antiseptic, antispasmodic, astringent, diuretic, rubefacient, stimulant and vermifuge[, ]. It is a valuable remedy used internally in the treatment of kidney and bladder complaints and is used both internally and as a rub and steam bath in the treatment of rheumatic affections[]. It is also very beneficial to the respiratory system and so is useful in treating diseases of the mucous membranes and respiratory complaints such as coughs, colds, influenza and TB[].
Applied externally in the form of liniment plasters, poultices, herbal steam baths and inhalers, it is a very beneficial treatment for a variety of skin complaints, wounds, sores, burns, boils etc[].

Agroforestry Uses:

The needles contain a substance called terpene, this is released when rain washes over the needles and it has a negative effect on the germination of some plants, including wheat[].

Other Uses

A tan or green dye is obtained from the needles[].

The plant is a source of oleoresins, which are obtained by tapping the trunk, or by destructive distillation of the wood[, ]. In general, trees from warmer areas of distribution give the higher yields[].
The resin contained in this species is very unusual in that it contains the hydrocarbon n-heptane and lower levels of terpenes than are found in other pine species. This is unmixed with other isomers of heptane and is formed by a very complex and little understood biochemical process. Its purity lead it to be used as the zero-point in the octane rating for petrol. In the past the n-heptane was distilled and used as an additive to raise the octane levels of petrol (gasoline), as well as being used for medicinal applications[].
Rosin is also obtained by distillation of pine resin. This is used in paper glue and soap manufacturing, as a constituent of varnishes and paints, and for coating the bows of stringed musical instruments such as violins[, ].
Pitch can also be obtained from the resin and is used for waterproofing, as a wood preservative etc[].

Wood - light, strong and fine-grained, it can vary from soft to hard[]. It is used for making furniture, boxes, toys etc[].
The tree is often cut and sold under the same name as Pinus ponderosa , but the sweetish odour of the freshly-cut wood of this species contrasts sharply with the turpentine odour of Pinus ponderosa[].

Propagation

It is best to sow the seed in individual pots in a cold frame as soon as it is ripe if this is possible otherwise in late winter. A short stratification of 6 weeks at 4°c can improve the germination of stored seed[]. Plant seedlings out into their permanent positions as soon as possible and protect them for their first winter or two[]. Plants have a very sparse root system and the sooner they are planted into their permanent positions the better they will grow[]. Trees should be planted into their permanent positions when they are quite small, between 30 and 90cm[]. We actually plant them out when they are about 5 - 10cm tall. So long as they are given a very good weed-excluding mulch they establish very well[]. Larger trees will check badly and hardly put on any growth for several years. This also badly affects root development and wind resistance[].
Cuttings. This method only works when taken from very young trees less than 10 years old. Use single leaf fascicles with the base of the short shoot. Disbudding the shoots some weeks before taking the cuttings can help. Cuttings are normally slow to grow away[].