Common Name: Singleleaf Piñon

General Information

Pinus monophylla is an evergreen tree with a much-branched, usually rounded, dense crown; it usually grows from 5 - 9 metres tall, occasionally reaching 14 metres. The bole is strongly tapering, around 50cm in diameter[, ].
The large, nutritious seeds were a staple food for native Americans, and are still gathered in quantity from the wild and often sold in local markets[], The tree also has a range of traditional medicinal uses and is a source of various materials. It is often grown as an ornamental.
Pinus monophylla has a large of occurrence. It can be sparse in some areas, but it is abundant in other locations and there is no evidence of any substantial decline. 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

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Range

Western N. America - Idaho, California, Nevada, Utah, Colorado, Arizona, ?New Mexico, northern Mexico (Baja Norte)

Habitat

Dry low-montane or foothill pinyon-juniper woodland, often forming extensive open forests; at elevations from 1,000 - 3,000 metres[, , , ].

Properties

Conservation Status	Least Concern
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Evergreen Tree
Height	10.00 m
Growth Rate	Slow
Pollinators	Wind
Self-fertile	No
Cultivation Status	Ornamental, Wild

Cultivation Details

Pinus monophylla is a moderately cold-hardy plant, able to tolerate temperatures down to around -20°c when fully dormant[]. It is found mainly in semi-arid regions where the mean annual precipitation is around 200 - 600mm, often concentrated in the winter and part of it falling as snow at higher elevations. It can be grown successfully in moister climes[].
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[, ]. This species succeeds in a hot dry position[]. Dislikes poorly drained moorland soils[]. Established plants tolerate drought[].
A slow growing tree in the wild, taking 25 years from sowing until it produces a crop[]. It then usually produces cones annually, with heavy crops every 2 - 3 years[].
The tree is long-lived, taking 250 - 350 years to reach maturity, with records of some specimens over 800 years old[, ].
The nearly globose seed cones can be 4 - 8cm in diameter. They take two growing seasons to come to maturity, shedding their seeds and falling soon thereafter[, ]
This is one of several species of pine that depend upon a mutualistic relationship with a species of bird (in this case Clark's nutcracker, Nucifraga columbiana) to disperse its seed. The birds have powerfull beaks which enable them to extricate the seeds and crack the shells. They store many of the seeds at some distance from the parent plant - some of these seeds never get eaten and can germinate and grow into new trees[].
This species is closely related to Pinus cembroides and considered to be no more than a sub-species of it by some botanists[]. The main difference is that this species has its leaves singly whilst Pinus cembroides has them in groups of two or three[].
This species is the state tree of Nevada[].
Plants are strongly outbreeding, self-fertilized seed usually grows poorly[]. They hybridize freely with other members of this genus[].
Plants in this genus are notably susceptible to honey fungus[].

Edible Uses

Seed - raw or cooked[, , , ]. Oily, with an agreeable almond-like flavour[, ], they are often used in sweetmeats, pastries, etc. They are the lowest in protein and fats and the highest in starch of the piñons[, ]. The seeds are an important food source for the local native peoples of Nevada and California[]. A good size, the seed is up to 20mm long[] and has a thin shell[].

The pitch obtained from the trunk is allowed to harden and is then used as a chewing gum[].

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

Medicinal

Single leaf piñon was employed medicinally by several native North American Indian tribes who valued it especially for its antiseptic and vulnerary properties and also for its beneficial effect on the respiratory system[]. It is little, if at all, used in modern herbalism.

The turpentine obtained from the resin of all pine trees is antiseptic, diuretic, rubefacient and vermifuge[]. It is a valuable remedy in the treatment of kidney and bladder complaints, and is used both internally and externally to treat rheumatic affections[, ]. It is also used in treating diseases of the mucous membranes, respiratory complaints, VD, TB, coughs, colds and influenza[, ]. A decoction is used to rid the body of tapeworms and other internal parasites[].
Externally it is used in the form of liniment plasters and inhalers[]. A poultice of the melted gum has been applied to cuts and sores[].

The heated pitch has been applied to the face as a depilatory[]. The pitch has also been used as a face cream to prevent sunburn[]. The heated pitch has been used as a poultice to treat sciatic pains and muscular soreness[].
The cooked pitch has been used by women to stop menstruation and thereby become infertile[]. It has also been given to adolescent girls to help them keep youthful and live a long life[].

The gum is used as a plaster on sores and cuts[].

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[].

Oleo-resins are present in the tissues of all species of pines, but these are often not present in sufficient quantity to make their extraction economically worthwhile[]. The resins 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[].
Oil of Turpentine consists of an average of 20% of the oleo-resin[] and is separated by distillation[, ]. Turpentine has a wide range of uses including as a solvent for waxes etc, for thinning and dissolving varnish and paints, a shoe polish, medicinal etc[, ].
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[].

The gum (this almost certainly means the resin[]) is used in waterproofing canoes, baskets, water containers etc, for repairing pottery vessels and in making turquoise mosaic[]. It is also used as an adhesive for mending pottery[].

The bark has been used as a roofing material in houses[].

The wood is light in weight, soft, weak and brittle[]. Of no value commercially, it is used locally, primarily for fence posts[].
The wood is used for fuel and is made into charcoal and used for smelting[]. It has a high combustibility and burns well, giving off a pleasant aroma as it burns[, ].

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[].