Common Name: Mexican Weeping Pine

General Information

Pinus patula is an evergreen tree with a conical crown becoming domed with age; it usually grows 12 - 30 metres tall, but can reach 40 metres The usually straight, cylindrical bole can be free of branches for up to 65% of the tree's height and around 100 - 120cm in diameter[, , ].
This is one of the most important pines for timber production in Mexico, growings quickly and producing a long, straight, fairly clear bole. It is also widely introduced in other warm temperate to tropical countries in plantation forestry, where in some cases it has become problematic as an invasive species. The tree also has a range of traditional uses, especially medicinal and as a source of materials. It is used in agroforestry, is planted in soil stabilization projects, used to provide shelter from the wind, as an ornamental and also to provide shade[, ].
Pinus patula is widespread and abundant despite exploitation for its timber. Regeneration is quick and the trees are fast growing. The plant is classified as 'Least Concern' in the IUCN Red List of Threatened Species(2013)[].
Widely used in forestry, especially in Africa, the tree has proved to be invasive of both fire-climax grasslands and woodland in regions where climatic conditions are close to those found in its natural range[].The plant has escaped from cultivation in S. Africa, for example, and become invasive in some areas there[].

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

Southern N. America - central and southen Mexico.

Habitat

Found in a variety of forest types, with conifers or with broad-leaved trees; at elevations from 1,500 - 3,000 metres[].

Properties

Weed Potential	Yes
Conservation Status	Least Concern
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Evergreen Tree
Height	30.00 m
Growth Rate	Fast
Pollinators	Wind
Self-fertile	No
Cultivation Status	Wild

Cultivation Details

Pinus patula grows in the subtropical to temperate highlands of central and southern Mexico, at elevations between 1,500 and 3,000 metres. It is found mainly in areas with abundant annual precipitation ranging from 1,000 - 2,200mm, though it can tolerate 750 - 3,000mm[, ]. In some areas fog can play a significant part in the availability of moisture through much of the dry season[]. It grows best in areas where annual daytime temperatures are within the range 18 - 29°c, but can tolerate 10 - 33°c[]. It is not a very cold-hardy plant, being able to tolerate short periods with temperatures down to around -10°c when fully dormant[]. Plants usually form multi-stemmed trees in areas subject to frost damage in the spring[].
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[, ]. Dislikes poorly drained moorland soils[]. Prefers a pH in the range 5.5 - 6.5, tolerating 4.5 - 7.5[]. Established plants tolerate drought[].
Early growth is quite rapid[]. Under favourable conditions trees may attain a height of 15 metres after 8 years and 35 metres after 30 years[].
Plants grow well in the temperate climate of southwest England (where there are specimens more than 15 metres tall) and in other areas with similar climates[].
The tree self-prunes poorly, so plantation trees are pruned when 4 - 6 year old to a height up to 2.5 metres in order to reduce fire hazard and improve access ('low pruning'). In pulpwood plantations no further pruning is done, although pruning up to a height of 6 metres has been recommended to reduce the risk of fire. For the production of sawn timber, dead as well as living branches up to a height of 7 or even 12 metres are removed to produce knot-free timber ('high pruning')[].
The production of viable seeds starts when trees are 5 years old, and is prolific in 8 - 10-year-old trees[].
The ovoid seed cones are 5 - 12cm long and 3 - 6cm wide. They take two growing seasons to come to maturity, opening and shedding their seed whilst still attached to the tree[].
Annual wood production potential is 15 - 40 cubic metres per hectare[].
Plants are strongly outbreeding, self-fertilized seed usually grows poorly[]. They hybridize freely with other members of this genus[].
This species is notably resistant to honey fungus[].

Edible Uses

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

The seeds of all Pinus species are more or less edible, and some are of good size and make very tasty and nutritious foods, often eaten in quantitiy. Others can be less desireable, either having a strongly resinous flavour, being bitter or, more commonly, rather too small and fiddly to make it very worthwhle even trying to eat them,
We have no specific information of the desireability of this species, though they are rather small (the size given includes the shell)[].
The ovoid seeds are 4 - 6mm long and 2 - 4mm wide[].

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[].

This species is used in Puebla to treat certain respiratory ailments such as cough[]..

Agroforestry Uses:

Pinus patula is an aggressive pioneer species that grows readily and rapidly in forest gaps created by fire[].
It is suitable for the reclamation of gullies, as the thick mat of fallen branchlets and needles retards surface run-off, limiting the advance of soil erosion[].
The tree is also planted in windbreaks[].
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 heartwood is pinkish to creamy white; it is not clearly demarcated from the sapwood. The grain is straight, spiral or wavy, texture fine; growth rings are distinct. The wood contains little resin, although numerous resin canals are present and prominent on the tangential surface. It has a faint odour. The wood is not durable, being susceptible to attacks by fungi, pinhole, longhorn, Anobium and marine borers, and termites. The sapwood is not susceptible to Lyctus borers. Air-drying properties are good, with only slight twisting of some boards. The dried wood is moderately stable to stable in service. The wood saws easily, but if fed too quickly a rough surface will result; it planes easily, but boring, mortising and turning properties are less favourable; it takes and holds nails well and glues easily. The wood of young trees is mainly used to manufacture boxes, and that of older trees for light construction, light flooring, joinery, ceilings, panelling, shingles, furniture, cabinet work, fence posts, poles, food containers, pallets, mine props, veneer and plywood. In Madagascar the wood is highly appreciated for glued laminated timber for carpentry and furniture, after the knots have been removed. It is also suitable for hardboard, particle board and wood-wool. It is an important source of pulpwood in South Africa[, ].
The wood is excellent fuel, and is also used for the production of charcoal[].

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[].