Common Name: Northern Pin Oak

General Information

Quercus ellipsoidalis is a deciduous tree with a rounded canopy; it usually grows up to 20 metres tall, occasionally to 40 metres[]. The lower trunk often retains the stubs of dead branches[].
The tree is harvested from the wild for local use as a medicine and source of materials. It is occasionally harvested commercially for its wood, is used in land rehabilitation projects and is also sometimes grown as an ornamental.
Quercus ellipsoidalis has a wide range and is often abundant. 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

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Range

Northern Central N. America - southwest Ontario, Minnesota, Wisconsin, Michegan, Iowa, Illinois, Indiana, Ohio

Habitat

Dry to moist siliceous to argillaceous woods[]. Dry sandy sites, rarely on moderately mesic slopes or uplands; at elevations from 150 - 500 metres[]. The best specimens are found in rich well-drained soils, especially those containing clay[].

Properties

Conservation Status	Least Concern
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Deciduous Tree
Height	20.00 m
Growth Rate	Medium
Pollinators	Wind
Cultivation Status	Wild

Cultivation Details

Quercus ellipsoidalis is a very cold-hardy tree, tolerating temperatures down to around -30°c when dormant. It grows best in areas with hot summers. In areas with cooler summers, such as the maritime regions of the temperate zone, it often grows poorly, failing to properly ripen its wood and suffering frost damage over the winter[, ].
Grows best in a sunny position[], though young plants tolerate reasonable levels of side shade[]. Easily grown in average, acidic, dry to medium moisture, well-drained soils[]. Tolerant of nutrient-poor soils[]. Prefers a good deep fertile loam which can be on the stiff side[, ]. Tolerant of somewhat alkaline soils[]. Plants are liable to become chlorotic, with yellowing leaves, in alkaline soils[]. Tolerates moderate exposure, surviving well but being somewhat stunted[]. Established plants are very drought tolerant[].
A moderately fast-growing tree in the wild[], it strts bearing seeds when around 20 years old[].
Seed production is cyclic, with 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[].
Seedlings soon develop a taproot and become intolerant of root disturbance, they should be planted into their permanent positions whilst young[].
The tree is well adapted to fire. The thermal insulating properties of the bark of mature trees allow it to survive even annual burning. Smaller trees are easily damaged by surface fires but will sprout vigorously from the root collar or stump after top-kill[].
Hybridizes freely with other members of the genus[]. It hybridizes in the wild with Quercus rubra and Quercus velutina[, ].
The lower branches are often shaded by other trees, with some branches eventually dying and breaking off leaving persistent pin-like stubs on the main trunk[].
Plants in this genus are notably resistant to honey fungus[].
Like many species in the Red Oak group, Quercus ellipsoidalis is susceptible to Oak Wilt, caused by the fungus Ceratocystis fagacearum. However, no reports of widespread decline affecting the population are currently available[].

Edible Uses

The seed is up to 20mm long[].
Although we have no specific information for this species, the seeds of all the species of oak are edible - indeed, several species have been used as staple foods, whilst most if not all have been used for food in times of shortage, when better foods were not available[].
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 is a coffee substitute[, , ].

Medicinal

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[, ].

A decoction of the inner bark has been used to treat suppressed menses caused by cold[].

Agroforestry Uses:

A useful species for rehabilitating disturbed sites. It has a deep root system, xeromorphic leaves, low water potential thershold for stomatal closure, and the ability to adjust osmotically. It can maintain high rates of photosynthesis during drought and survives on nutrient-poor soils[].

Other Uses

The leaves of most species in this genus are more or less rich in tannins. A mulch of the partially decayed leaves can be placed around vulnerable plants in order to repel slugs, snails, grubs etc, and these will in time break down to add humus and nutrients to the soil. Fresh leaves should be used with caution, however, since as these decay they utilize some of the nitrogen in the soil and thus can 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 and is also used by many cultures to make ink[, ].
The bark of oak trees is also usually rich in tannins and can be used as a dyestuff and for waterproofing rope[, ].

The wood is hard, heavy and strong. It is cut occasionally for lumber, also being used for flooring, furniture and interior finishes[].
The wood of many Oak species is a favoured fuel - burning 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. 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.