Pinus aristata

• Bristle-Cone Pine

Notes

Cultivation

Thrives in a light well-drained sandy or gravelly loam^[11]. Dislikes poorly drained moorland soils^[11]. Established plants tolerate drought^[2]. A wind tolerant tree, it often grows on very exposed ridges in the wild^[12]. Trees grow best in areas with cold dry summers, the largest cultivated specimen is in dry sub-continental north-east Iceland^[2]. A very slow growing^[13] (to 6 metres in 60 years at Kew) and short-lived tree in Britain, though it lives for 2000 years or more in its native range^[9][14]. This is the oldest known living plant with specimens over 4000 years old^[15]. This species is closely related to P. balfouriana^[9]. The cones open and shed their seed whilst still attached to the tree^[16]. Plants are strongly outbreeding, self-fertilized seed usually grows poorly^[2]. They hybridize freely with other members of this genus^[2]. Leaf secretions inhibit the germination of seeds, thereby inhibiting the growth of other plants below the tree^[17]. Plants in this genus are notably susceptible to honey fungus^[2].

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^[18]. Plant seedlings out into their permanent positions as soon as possible and protect them for their first winter or two^[9]. Plants have a very sparse root system and the sooner they are planted into their permanent positions the better they will grow[K]. Trees should be planted into their permanent positions when they are quite small, between 30 and 90cm^[2]. 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[K]. Larger trees will check badly and hardly put on any growth for several years. This also badly affects root development and wind resistance^[2]. 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^[13].

Range

South-western N. America - Colorado to New Mexico.

Habitat

Dry rocky slopes, often in pure stands, 2250 - 3450 metres in California^[10]. Trees grow right up to the tree line, where they are no more than gnarled shrubs^[12].

Known hazards

The wood, sawdust and resins from various species of pine can cause dermatitis in sensitive people^[19].

Edible uses

Seed - raw or cooked^[1]. Up to 6mm long^[2]. The oil-rich seed has a slightly resinous flavour. A vanillin flavouring is obtained as a by-product of other resins that are released from the pulpwood^[2].

Material uses

A tan or green dye is obtained from the needles^[5]. The tree could be the source of antioxidants that contribute to long life^[1]. 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^[6]. 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^[7]. The resins are obtained by tapping the trunk, or by destructive distillation of the wood^[3][7]. In general, trees from warmer areas of distribution give the higher yields^[7]. Turpentine consists of an average of 20% of the oleo-resin^[7] and is separated by distillation^[3][7]. Turpentine has a wide range of uses including as a solvent for waxes etc, for making varnish, medicinal etc^[3]. Rosin is the substance left after turpentine is removed. This is used by violinists on their bows and also in making sealing wax, varnish etc^[3]. Pitch can also be obtained from the resin and is used for waterproofing, as a wood preservative etc. Wood - light, soft, not strong. Used for fuel and mining timber^[8].

Medicinal uses

The turpentine obtained from the resin of all pine trees is antiseptic, diuretic, rubefacient and vermifuge^[3]. 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^[3]. 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^[3]. Externally it is a very beneficial treatment for a variety of skin complaints, wounds, sores, burns, boils etc and is used in the form of liniment plasters, poultices, herbal steam baths and inhalers^[3][4].