Common Name: Apache Pine

General Information

Pinus engelmannii is an evergreen tree with an irregularly rounded, rather thin crown; it can grow up to 35 metres tall. The straight, cylindrical bole is up to 60cm in diameter. The tree develops a deep taproot[].
The tree is often harvested commercially for its wood, usually as a component of various other pine woods[]. It is grown as an ornamental[].
Pinus engelmannii is very widespread in Mexico and in many places common. 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

Southwestern N. America - southern Arizona, southern New Mexico to northern Mexico

Habitat

High and dry mountain ranges, valleys, and plateaux, growing in open pine and pine-oak woodland, sometimes in mixed pine forest; at elevations from 1,500 - 2,500 metres[, ].

Properties

Conservation Status	Least Concern
Edibility Rating
Other Uses Rating
Habit	Evergreen Tree
Height	20.00 m
Pollinators	Wind
Cultivation Status	Ornamental, Wild

Cultivation Details

Pinus engelmannii is a somewhat cold-hardy plant, able to tolerate temperatures down to around -10°c when fully dormant. It grows well in regions with relatively mild winters and (moderately) warm summers, coming from a region where, at higher elevations, frost and snow are common in winter[]. The mean annual rainfall ranges from 400 - 700mm, increasing southward[].
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 is found in the wild on poor rocky (volcanic) soils as well as on alluvial coarse sand/gravel or loamy sand[].
The trunk has a rather thick layer of bark which helps to protect it from fire damage[].
The seed cones take two growing seasons to reach maturity, shedding their seeds soon thereafter, and then falling from the tree[].
This is one of several Pinus species that have a juvenile life stage. After germinating, the seedlings produce secondary foliage but the central shoot does not elongate - at this stage the plant looks more like a bunchgrass than a pine. Especially when growing in shade, the plant can remain in this juvenile stage for several years, developing a large taproot but not increasing in height. If the light levels increase (due to removal of tree cover by fire, deforestation or some other reason) then the plant commences rapid height growth[].
Plants in this genus are notably susceptible to honey fungus[].

Edible Uses

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)[].
Seeds obovoid; body ca. 8--9mm, dark brown[].

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[].

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 wood is of similar quality to Pinus ponderosa and is used similarly[].
Pinus ponderosa wood is light in weight, strong, fine-grained and pleasantly aromatic. It can vary from soft to hard[, , , , , ]. It is an important lumber tree, used generally for making furniture, boxes, toys, posts etc, whilst the higher grade and larger size wood is much used in light construction like window frames, doors, stairs, flooring, sidings, panelling, veneers and for furniture and cabinetwork[, , , , , , ].

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[].