Common Name: Pin Oak

General Information

Quercus palustris is a deciduous tree with a moderately dense, pyramidal crown; it usually grows up to 25 metres tall, occasionally reaching 40 metres. The common name arises from the small dead branches (pins) that persist on the trunk[].
The tree is harvested from the wild for local use as a food, medicine and source of materials. It is sometimes harvested on a commercial basis for its wood, and is occasionally cultivated as a timber crop. It is widely planted as an ornamental shade tree both in North America and in Europe[].
Quercus palustris is widespread throughout the central eastern United States and into Canada, it has a stable population and there are no reports of major decline. The plant is classified as 'Least Concern' in the IUCN Red List of Threatened Species(2013)[].

Known Hazards

All parts of the plant contain tannins. Whilst tannins are found in many foods, and have a range of medicinal uses. They are usually only present in low concentrations. In some foods made from oaks (particularly the seeds), the tannin content can be quite high unless the food is treated to reduce tannin content.
Tannins are only of low toxicity and, because of their bitter taste and astringency, are unlikely to be eaten in large quantities. However, if they are taken in excess, they can cause stomach pains; constipation followed by bloody diarrhoea: excessive thirst; and excessive urination[].

Botanical References

, ,

Range

North-eastern and Central N. America - Illinois and Michigan to Connecticutt, south to eastern Oklahoma, Arkansas and North Carolina

Habitat

Deep rich soils[, ] in swampy woods and bottoms at low elevations[]. Often found in wet, poorly drained claypan soils typical of floodplains, tolerating short periods of spring flooding[].

Properties

Conservation Status	Least Concern
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Deciduous Tree
Height	15.00 m
Growth Rate	Fast
Pollinators	Wind
Cultivation Status	Cultivated, Ornamental, Wild

Cultivation Details

Young plants tolerate reasonable levels of side shade but older plants grow better in a sunny position[, ]. Prefers a good deep fertile loam which can be on the stiff side[, ]. Prefers an acid soil[], plants are somewhat lime tolerant according to one report[], whilst others say that they are intolerant of alkaline soils[, ]. Plants are tolerant of long periods with the soil inundated[]. Withstands atmospheric pollution[]. Tolerates moderate exposure, surviving well but being somewhat stunted[].
A fairly fast growing tree[], it is occasionally cultivated for timber in eastern central Europe[]. It coppices fairly well[].
The tree seldom lives longer than 150 - 200 years in the wild, commencing to bear seeds when 15 - 25 years old[]. Seed production is cyclic, a year of high yields being followed by 2 - 3 years of low yields[]. The tree flowers on new growth produced in spring, the seed taking two summers to ripen[].
There are some named varieties selected for their ornamental value[].
Intolerant of root disturbance, trees should be planted in their permanent positions whilst young[]. This species has a relatively shallow tap-root, making it easier to transplant[].
Hybridizes freely with other members of the genus[].
Pin Oak is susceptible to Oak Wilt (Ceratocytis fagacearum) and other common pests and pathogens of the Red Oak group in the eastern US. However, no reports of widespread population decline are available, suggesting this does not currently pose a major threat to the species[].
Plants in this genus are notably resistant to honey fungus[].

Edible Uses

Seed - cooked[]. The seed is about 20 - 25mm long and 15mm wide[]. High in carbohydrates and fat, but low in protein[].
The seed is usually cooked before eating, though it can also be eaten raw. It can be eaten whole, though it is more commonly dried, then ground into a powder and used as a thickening in stews etc or mixed with cereals for making bread.
In some species, especially many of those classified as 'white oaks', the seeds are low in tannins and have a more or less sweet and agreeable flavour. The seed of most species, however, have a very bitter flavour, due especially to the presence of tannins. In these species there are various processes that can remove or at least reduce the amount of these bitter substances (although other water-soluble substances, including some minerals, will also be removed).
Tannins are water-soluble and therefore the easiest way to remove or reduce tannin levels is by soaking in water. A few different methods are listed:-
A traditional method of preparing the seed was to bury it in boggy ground overwinter and allow the wet soil to gradually leach the tannins. The germinating seed was dug up in the spring when it would have lost most of its astringency and bitterness.
Another method was to wrap the seeds in a cloth bag and place them in a stream for several weeks.
Drying the seed and grinding it to a powder before soaking speeds up the process. The fastest method is to use hot water, by cooking the powder and changing the water several times until the cooking water is no longer bitter. Alternatively, you can use cold water (which is reported to produce the best quality flour). In this case, you soak the powdered seed in cold water for 12 - 24 hours then discard the water. Repeat this process for a number of times until the soak water is no longer bitter.

The roasted seed of many Quercus species has been used as a coffee substitute.

Medicinal

An infusion of the inner bark has been used to treat intestinal pains[].

Quercus (oak) species are used in the traditional medicine of many cultures, being valued especially for their tannins. Various parts of the plant can be used, most frequently it is the leaves, bark, seeds, seed cups or the galls that are produced as a result of insect damage. A decoction or infusion is astringent, antibacterial, antifungal, antiseptic, styptic and haemostatic. It is taken internally to treat conditions such as acute diarrhea, dysentery and haemorrhages. Externally, it is used as a mouthwash to treat toothache or gum problems and is applied topically as a wash on cuts, burns, various skin problems, haemorrhoids and oral, genital and anal mucosa inflammation[]. Extracts of the plant can be added to ointments and used for the healing of cuts[, ].

Agroforestry Uses:

The tree is recommended for the restoration of graded/top-soiled mine spoils. In southern Illinois, seedlings (both planted and direct seeded) had among the best survival and growth of nine oak species tested on graded cast
overburden covered with about 40cm of eroded old field surface soil. The tree has also naturally established itself on surface-mined lands in Missouri, Kansas, and Oklahoma[]

Other Uses

The leaves of most species in this genus are more or less rich in tannins. A mulch of the leaves can be placed around vulnerable plants in order to repel slugs, snails, grubs etc. Fresh leaves should be used with caution, since these can utilize some of the nitrogen in the soil and this inhibit plant growth[, ].

Oak galls are excrescences that are sometimes produced in great numbers on the tree and are caused by the activity of the larvae of different insects. The insects live inside these galls, obtaining their nutrient therein. When the insect pupates and leaves, the gall can be used as a rich source of tannin, that can also be used as a dyestuff[]. A black ink is made from the galls[].

The wood is strong, hard, coarse grained, heavy, often knotty owing to the persistence of many small limbs[, , , , ]. It weighs 43lb per cubic foot[]. It is occasionally used for shingles, clap-boards, furniture, wooden nails etc and as a fuel[, , , , , ].
While Pin Oak does not produce high quality lumber, the wood can be used for construction timbers[].
A good fuel, buring well and giving off a lot of heat[].

Propagation

Seed - it quickly loses viability if it is allowed to dry out. It can be stored moist and cool overwinter but is best sown as soon as it is ripe in an outdoor seed bed, though it must be protected from mice, squirrels etc. Small quantities of seed can be sown in deep pots in a cold frame. Average germination rate is about 68%[]. Plants produce a deep taproot and need to be planted out into their permanent positions as soon as possible, in fact seed sown in situ will produce the best trees[]. Trees should not be left in a nursery bed for more than 2 growing seasons without being moved or they will transplant very badly.