Quercus Sp. - Oak

Fagaceae - Oak Family [E-flora]

± 600 species: northern hemisphere, to northern South America, India. (Latin: ancient name for oak) [Manos et al. 1999 Molec Phylogen Evol 12:333–349] Many named hybrids; those (3) treated here form widespread populations; most others occur as single individuals, and some but not all of these are mentioned here, under the first parent treated (alphabetically). Reproduction of many species declining due to habitat degradation or loss as well as disease.
Unabridged references: [Manos, P. S., Doyle, J. J., & Nixon, K. C. 1999. Phylogeny, biogeography, and processes of molecular differentiation of Quercus subgenus Quercus (Fagaceae). Molec Phylogen Evol 12: 333–349.][Jepson2012]

Local Species;

1. Quercus garryana - Garry oak [TSFTK][PCBC][E-flora]
2. Quercus robur - English oak [E-flora]

(Above images)

Quercus garryana - Garry Oak

"Garry oak (Quercus garryana) ecosystems are among the most endangered in Canada. Only an estimated 1–5% of the 1850s distribution remains in a near-natural state, providing habitat for more than 100 species considered at risk either nationally or provincially. Although habitat fragmentation and isolation threaten the long-term viability of Garry oak–associated species, all habitat remnants have been degraded by exotic species of plants and animals, and many suffer from the effects of fire suppression." [Apostol RPNW]

Description

• General Deciduous Tree growing to 18 m (59ft) by 10 m (32ft) at a slow rate.PFAF-1 Often small and shrubby. Light grey bark (IFBC)E-flora with thick furrows and ridges. PCBC2004
• Habitat Dry grasslands and rock outcrops in lowland.(IFBC)E-flora-1 The plant can tolerates strong winds but not maritime exposure.PFAF-1 "...sometimes found on deep, rich, well-drained soil". PCBC2004
• Range SE Vancouver Island & the Gulf islands. South to California.(IFBC)E-flora-1
  
• Status Native.^E-flora-1
  
• Ecological Indicator Shade-intolerant. "Occurs in maritime to submaritime summer-dry cool mesothermal climates on very dry to moderately dry soils;...Usually forms open-canopy stands on water-shedding (rock outcrops) sites. Its calcium-rich bark supports corticolous moss communities."(IPBC)E-flora-1
  
• Similar Species In B.C. "...most easily confused with the introduced English oak (Quercus rubur)." "...In English oak, leaf lobing is shallow, less than halfway to the midrib, while in Garry oak lobing often extends more than halfway to the midrib." Hybridization can make oaks difficult to differentiate.E-flora-1 Hybrids are less of a problem in the Pacific Northwest than in southern Oregon and California, where several species are present. PWOBC

Hazards

• Tannins are "...present in the acorns and leaves of oaks (Quercus spp.), making them extremely bitter and potentially toxic. Even edible types of acorns... usually must have their tannins removed through leaching." CPPlantMush Quercus Sp.; "The unleached nuts are inedible because they contain up to 6% percent tannin. This is quite toxic if ingested in quantity and can damage the liver." Tozer UWP

Food Uses

• Seed: "...raw or cooked(226). It has a sweet taste(229). The seed is ground into a powder and used in making bread etc, it is a good thickener for soups and stews(183).... The roasted seed is a coffee substitute."PFAF-1 Acorns eaten "by all of the Vancouver Island Salish groups (Barnett, 1955)." Turner&Bell
  
• Leaching Tannins: "The seed has a high content of bitter tannins, these can be leached out by thoroughly washing the dried and ground up seed in water(183), though many minerals will also be lost. Either the whole seed can be used or the seed can be dried and ground it into a powder. It can take several days or even weeks to properly leach whole seeds, one method was to wrap them in a cloth bag and place them in a stream. Leaching the powder is quicker. A simple taste test can tell when the tannin has been leached. The traditional method of preparing the seed was to bury it in boggy ground overwinter. The germinating seed was dug up in the spring when it would have lost most of its astringency." PFAF-1
• "They were first steamed, roasted, or boiled for a long time to remove the tannin (Paul,1968). The Island Salish did not leach them to the extent of the Oregon and California Indians, where acorns were the staple food." Turner&Bell "Some people stored them all winter in baskets buried in the damp mud, a practice which would have helped dispel the tannins." [Turner&Kuhnlein]

Other Uses

• Tannin: "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(4)."PFAF-1
  Wood: "Hard, heavy, strong, tough, close grained, durable, easy to split. Used for furniture, cabinet making, general construction etc and also for fence posts and fuel(46, 61, 82, 171, 226, 229)."PFAF-1

Medicinal Uses

• Plant: "An infusion of the plant has been drunk by a mother before her first baby comes (257)." PFAF-1
  
• Bark: "A decoction of the bark has been used in the treatment of tuberculosis(257).... The pounded bark has been rubbed on the abdomen and sides of the mother before her first delivery(257)."PFAF-1
  
• Galls: "Any galls produced on the tree are strongly astringent and can be used in the treatment of haemorrhages, chronic diarrhoea, dysentery etc(4)." PFAF-1

Nutritional

• Quercus Sp.; Leached acorns contain from 5 - 20% fat, 2- 5% protein, 50 - 70% carbohydrate and lots of minerals.Tozer UWP Analysis of acorn meal has shown it to be 65% carbohydrates, 18% fat, and 6% protein. Nyerges
• Quercus garryana Nuts: 9g water, 3.9g protein, 4.5g fat, 68.9g carbohydrates, 12g fiber, 1.8g ash per 100g fresh weight. [Turner&Kuhnlein]

Cultivation

"Lime tolerant (188). Young plants tolerate reasonable levels of side shade(200). Tolerates moderate exposure, surviving well but being somewhat stunted(200).... A slow-growing and drought tolerant tree(188, 229), it can live for 500 years(229). Seed production is cyclic, with a year of high production being followed by 2 - 3 years of lower yields(229). The tree flowers on new growth produced in spring, the seed ripening in its first year(200, 229). Intolerant of root disturbance, trees should be planted in their permanent positions whilst young(11). Hybridizes freely with other members of the genus(200). Plants in this genus are notably resistant to honey fungus(200)." PFAF-1

"White oak communities, Franklin and Dyrness reveal, come in several varieties, each named for the most prevalent understory shrub. These communities are called white oak/hazelnut, white oak/serviceberry, and gulp white oak/poison oak, which unfortunately is all too common around here. Each community contains a dozen or more associated plants...The tree also takes a decade or more to bear acorns..." [Hemenway GG]

Fire Regime: "Kalapuya and other local Native American groups were some of the first people to shape Willamette Valley ecosystems to meet their needs. Prior to European settlement they used fire as a management tool to maintain gardens of camas (Camassia quamash), a native prairie plant whose starchy bulb was a food staple, and to foster the growth of tarweed, grasshoppers, nut and berry plants, and bracken fern rhizomes (Agee 1993; Boyd 1999). They also set fires to herd deer for hunting. Oregon white oak (Quercus garryana) is adapted to fire in ways that other species are not. Its thick bark protects the delicate cambium, and dormant buds are located low on the root collar below the soil surface so they can sprout even after fire (Tveten and Fonda 1999). The fires the Kalapuya set thinned the understory of the oak woodlands and savannas, maintaining the stands’ open structure, enhancing tree vigor and seedling regeneration, and increasing mast crops for consumption by both humans and game (Agee 1993, 1996; Boyd 1999; Peter and Harrington 2002; Van Lear and Brose 2002). The fires also limited infestations by invasive plants and acorn-boring insects (Anderson 2005). The net effect of Kalapuyan management was to create an overstory of widely spaced, large-crowned Oregon white oak trees with an understory of shrubs and perennial native grasses (Agee 1990)." [Egan HDER]

''Burning was in the fall of the year when the plants were all dried up when it was going to rain. They’d burn areas when they would see it’s in need. If the brush was too high and too brushy it gets out of control. If the shrubs got two to four feet in height it would be time to burn. They’d burn every two years. Both men and women would set the fires. The flames wouldn’t get very high. It wouldn’t burn the trees, only the shrubs. They burned around the camping grounds where they lived and around where they gathered. They also cleared pathways between camps. Burning brush helped to save water. They burned in the valleys and foothills. I never heard of the Indians setting fires in the higher mountains, but don’t take my word for it. (Rosalie Bethel, North Fork Mono, pers. comm. 1991)'' [Anderson TTW]

Propagation

The seed "...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(11). Trees should not be left in a nursery bed for more than 2 growing seasons without being moved or they will transplant very badly." PFAF-1

• Seed Collection: "Separate insect-damaged from sound seeds by presence of bore holes, and by floating off unsound acorns in water." GOERT
  
• Fruit/Seed Dormancy and Treatment: "No dormancy exhibited, thus no treatment required." GOERT Treatment: soak 48 hours, incubation: 20C for 28 days. [Leadem FSSB]
  
• Vegetative Propagation: "Possible but not recommended for practical propagation operations." GOERT
  
• Outplanting Characteristics and Requirements: "Seedlings can take 10 or more years to grow to 1 m in height. If possible, plant seed where they are intended to grow because seedlings do not transplant well." GOERT "It is slow growing but very long-lived." "Site: Prefers well-drained soils in full sun." [Steiner NCG]
  
• Care: "Prune in winter only as needed. Never prune in summer, when oak wilt can be transmitted by beetles attracted to pruning wounds. Oaks are very sensitive to soil compaction, so care should be taken when heavy construction equipment is used around their roots. Iron chlorosis is a problem if soil pH is too high. Several nonserious problems affect oaks, including galls, scale, anthracnose, and lace bug. The most serious problem is oak wilt, which can be fatal." [Steiner NCG]

Quercus robur - English Oak

Identification
English Oak is an introduced European species in North America, where it is widely cultivated. It is reported from several US states ((MA, ME, NH, NY, OH, PA, RI), and five Canadian provinces (BC, NB, NS, ON, PE) (USDA 2010). While it is widely grown, it is naturalized only in Washington, New Brunswick and Nova Scotia (Flora North America Online 2010). In British Columbia, it is also naturalized,and is frequently encountered in the southwestern corner of the province, where it persists in areas where acorns have been introduced as squirrel food, or where it has been planted. It is often encountered as seedlings or young saplings under a forest canopy in drier sites near urban areas, particularly in areas of peat soil. Wild plants have been collected by Lomer in Squamish and on Sumas Mountain and it is frequent in drier parts of the Lulu Island Bog in Richmond. [E-flora]
Taxonomically, this is a tree species of oak in the white oak group (Quercus section Quercus). It most closely resembles the eastern North America white oak (Quercus alba). In British Columbia, it resembles Garry oak (Quercus garryana), but may be separated based on leaf lobing, leaf petiole length, and acorns. It reaches heights of 30 m and has shallowly lobed leaves with leaf stalks 1-3 mm in length. Fruits (acorns) occur on long stalks. [E-flora]

General: Deciduous spreading tree up to 30 m tall; bark light grey with thick scaly ridges. [IFBC-E-flora]

Similar Species
In British Columbia, English oak is most easily confused with the native Garry oak (Quercus garryanna). The two species may be separated by characteristics of leaf lobing, leaf stalks, and acorn morphology. In English oak, leaf lobing is shallow, less than halfway to the midrib, while in Garry oak lobing often extends more than halfway to the midrib. Leaf petioles in English oak are 1-3 mm long, while in Garry oak they are 1-2 cm long. English oak acorns have relatively long stalks, while Garry oak acorns are stalkless. Identification in oaks can be challenging because of the frequency of hybridization. [E-flora]

Hazards

• Possible digestive complaints. May delay absorption of alkaloids and other alkaline drugs [301].[PFAF] Contraindications: Whole-body baths are contraindicated with large-area weeping eczemas and skin injuries, with feverish and infectious illnesses, with cardiac insufficiency in stages III and IV (NYHA) and with hypertonia in stage IV (WHO). [PDR]

Edible Uses

• Seed - cooked[2, 5, 8, 13]. Nourishing but indigestible[4]. Chopped and roasted, the seed is used as an almond substitute[8]. It can be dried, ground into a powder and used as a thickening in stews etc or mixed with cereals for making bread[183]. The seed contains bitter tannins, these can be leached out by thoroughly washing the seed in running water though many minerals will also be lost[63]. Either the whole seed can be used or the seed can be dried and ground it into a powder. It can take several days or even weeks to properly leach whole seeds, one method was to wrap them in a cloth bag and place them in a stream. Leaching the powder is quicker. A simple taste test can tell when the tannin has been leached. The traditional method of preparing the seed was to bury it in boggy ground overwinter. The germinating seed was dug up in the spring when it would have lost most of its astringency. The roasted seed is a coffee substitute[21, 61]. [PFAF].
  
• Gum: An edible gum is obtained from the bark[177]. Another report says that an edible manna is obtained from the plant and that it is used instead of butter in cooking[183]. This report probably refers to the gum[K].[PFAF]

Other Uses

• Wood - hard, tough, durable even under water - highly valued for furniture, construction etc[4, 13, 61, 66]. It is also a good fuel[6] and charcoal[61].Trees can be coppiced to provide material for basket making, fuel, construction etc[23]. The wood is a source of tar, quaiacol, acetic acid, creosote and tannin[123]. [PFAF]
  
• Galls: 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[4]. A black dye and an excellent long-lasting ink is made from the oak galls, mixed with salts of iron[4, 7, 66]. The colour is not very durable[4]. When mixed with alum, the dye is brown and with salts of tin it is yellow[4].[PFAF]
  
• Bark: The bark is very rich in calcium[18]. Tannin is extracted commercially from the bark and is also found in the leaves[223]. On a 10% moisture basis, the bark contains11.6% tannin and the wood 9.2%[223]. The bark strips easily from the wood in April and May[4]. A purplish dye is obtained from an infusion of the bark with a small quantity of copperas[4]. It is not bright, but is said to be durable[4].[PFAF]

Medicinal Uses

The oak tree has a long history of medicinal use. It is anti-inflammatory, antiseptic, astringent, decongestant, haemostatic and tonic[4, 7, 9, 13, 21, 165]. The German Commission E Monographs, a therapeutic guide to herbal medicine, approve Quercus robur Pedunculate Oak for coughs/bronchitis, diarrhoea, inflammation of mouth and pharynx, inflammation of the skin (see [302] for critics of commission E).[PFAF]

• Bach: The plant is used in Bach flower remedies - the keywords for prescribing it are 'Despondency', 'Despair, but never ceasing effort'[209]. A homeopathic remedy is made from the bark. It is used in the treatment of disorders of the spleen and gall bladder[9]. [PFAF].
  
• Preparation: The flower essence remedy Oak is prepared employing the sun method. To prepare this Bach Flower Remedy you need to select a place close to an oak wood having an open southern aspect and collect only the red hued female flowers from several different trees - as many as you can. It is important to collect the flowers with their entire stalk and then float them on water in a bowl. While the flowers should cover the surface of the water, the bowl needs to be positioned such that it receives maximum sunlight.
  
• Uses: A Bach Flower Remedy, Oak is specially meant to cure conditions of stoic diligence and tenacity of willpower even when confronted with adversity.[Herbs2000]
  
• Bark: The bark is the part of the plant that is most commonly used[4], though other parts such as the galls, seeds and seed cups are also sometimes used[7]. A decoction of the bark is useful in the treatment of chronic diarrhoea, dysentery, intermittent fevers, haemorrhages etc[4]. Externally, it is used to bathe wounds, skin eruptions, sweaty feet, piles etc[9]. It is also used as a vaginal douche for genital inflammations and discharge, and also as a wash for throat and mouth infections[9]. The bark is harvested from branches 5 - 12 years old, and is dried for later use[9]. [PFAF]
  
• Galls: Any galls produced on the tree are strongly astringent and can be used in the treatment of haemorrhages, chronic diarrhoea, dysentery etc[4].[PFAF]
  
• Smoke: According to Avicenna, Persians inhaled smoke from burning wood to relieve diarrhea and to reduce pain (Mohagheghzadeh et al. 2006). [UAPDS]

Medicinal Parts: The medicinal parts are the dried bark of the young branches and the lateral shoots, the dried bark of the trunk and branches, the dried leaves of various oak species and the seed kernels without the seed coats. …Oak bark is harvested from March to April. The trees fall every 10 years. The bark is dried rapidly.

Compounds
Catechin tannins: oligomeric proanthocyanidins
Ellagitannins: (including castalagin, pedunculagin, vesvalagin, 2,3-(S)-hexahydroxy diphenoyl glucose), flavano-ellagitannins (acutissimins A and B, eugenigrandin, guajavacin B, stenophyllanin C) Gallo tannins Monomeric and dimeric catechins and leucocyanidins Tannins (12 to 16%)
Effects: The drug, which contains tannins, is astringent, antiphlogistic, antiviral and anthelmintic. [PDR]

Indications and Usage
Approved by Commission E: • Cough/bronchitis • Diarrhea • Inflammation of the mouth and pharynx • Inflammation of the skin [PDR]

Unproven Uses: Oak is used internally for non-specific diarrhea. In smaller doses it is used as a stomach tonic. The drug is used externally for inflammatory skin diseases, inflammation of the mouth and throat as well as the genital and anal area, suppurating eczema, hyperhydrosis, intertrigo and as an adjuvant treatment of chilblains. Oak is also used in folk medicine internally for hemorrhagic stool, non-menstrual uterine bleeding, hemoptysis and chronic inflammation of the gastrointestinal tract. External uses include hemorrhoid bleeding, varicose veins, uterine bleeding, vaginal discharge (washes/douches), rashes, chronic, itching, scaley and suppurating eczema and eye inflammations. [PDR]

Precautions & Adverse Effects

• General: No health hazards or side effects are known in conjunction with the proper administration of designated therapeutic dosages. Internal administration could lead to digestive complaints because of the secretion-inhibiting effect of the tannins. [PDR]
  
• Dosage: Mode of Administration: Oak is available as whole, crude and powdered drug form, as a bath additive and in compounded preparations. It is also available in solid pharmaceutical form for oral intake. [PDR]
  
• Preparation: Tea — 1 gm finely cut or coarse powdered drug is put in cold water, rapidly boiled and strained after some time (1 teaspoon corresponds to 3 gm drug). Bath additive — 5 gm drug is boiled with 1 Liter water and added to the full or hip bath. [PDR]
  
• Daily Dosage: Internally — 3 gm of drug; Tea: 1 cup 3 times a day. Externally — Rinses/gargles: boil 2 dessertspoons finely cut drug with 3 cups water. Bath additive — duration: 20 minutes at 3 2 to 37^o C.
  
• Storage: Should be tightly sealed and protected from light.[PDR]

Cultivation
Mulch: A mulch of the leaves repels slugs, grubs etc, though fresh leaves should not be used as these can inhibit plant growth[20, 201].[PFAF]
Herbal Compost: The bark is an ingredient of 'Quick Return' herbal compost activator[32]. This is a dried and powdered mixture of several herbs that can be added to a compost heap in order to speed up bacterial activity and thus shorten the time needed to make the compost[K].[PFAF]

Prefers a good deep fertile loam which can be on the stiff side[11]. Young plants tolerate reasonable levels of side shade[200]. Succeeds in heavy clay soils[13] and in wet soils so long as the ground is not water-logged for long periods[186]. Dislikes dry or shallow soils but is otherwise drought tolerant once it is established[186]. Tolerant of exposed sites though it dislikes salt-laden winds[186]. The oak is a very important timber tree in Britain, it is also a very important food plant for the caterpillars of many species of butterfly[30], there are 284 insect species associated with this tree[24]. It has often been coppiced or pollarded for its wood in the past[23], though this should not be done too frequently[186], about once every 50 years is the average. The tree flowers on new growth produced in spring, the seed ripening in its first year[200, 229]. Older trees have a thick corky bark and this can protect them from forest fires, young trees will often regenerate from the base if cut down or killed back by a fire[186]. Intolerant of root disturbance, trees should be planted in their permanent positions whilst young[11]. Hybridizes freely with other members of the genus[200]. Immune to attacks by the tortix moth[1]. This species is notably resistant to honey fungus[88, 200].[PFAF]

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[11]. Trees should not be left in a nursery bed for more than 2 growing seasons without being moved or they will transplant very badly.[PFAF]

Uses of Related Sp.

"All acorns are good to eat. Some are less sweet than others, that's all. But the bitterness that is prevalent in different degrees is due to tannin....The oaks may be separated into two great groups: the white oaks and the red oaks. The acorns of the former are the sweet ones....Indians leached their bitter acorns in a number of ways. Sometimes the acorns would be buried in swamp mud for a year, after which they would be ready for roasting and eating whole. Other tribes let their shelled acorns mold in baskets, then buried them in clean freshwater sand. When they had turned black, they were sweet and ready for use. " Angier FFWE "Many of the sweet acorns borne by the White Oak group are not at all unpleasant eaten raw. Gibbons SHH "Only the scrub Oaks were not generally used by the Indians, though even these were taken in times of acute shortage of other food." EUCP

Quercus Sp.
It has been said that the Oaks produce more nuts annually than all other wild and cultivated nut trees combined. Tozer UWP

• Hazards: Livestock often die within 24 hours of consuming the young foliage and bark. KYP James
  
• Preparation: Prepared as "...Acorn Grits and Acorn Meal, and neither is very difficult to prepare. Acorn Grits are made of shelled-out acorn kernels, boiled for two hours, with several changes of water.... then thoroughly dried in a slow oven and ground rather coarsely. Acorn Meal is made by grinding dry, raw acorn kernels, mixing the meal with boiling water and pressing out the liquid through a jelly bag. This process might have to be repeated several times with very bitter acorns. Then the meal is spread thinly in shallow pans and dried in the sun or in a very slow oven." It can become caked during this process so it must be reground. Gibbons SHH "A better method is to peel the acorns, place them in a container, and cover with water. Pour out the water after 24 hours and replace with fresh warm water. Three or four changes of water with this non-boiling method should be sufficient to leach out all of the tannic acid." Nyerges
  
• Storage: "Both the meal and the grits can be stored in sealed glass jars, where they seem to keep indefinitely." Gibbons SHH "Prepared acorn meal can be dried and stored, but it tastes much better when fresh, so usually only small amounts were ground and leached at one time." Tozer UWP
  
• Oil: "Some tribes apparently extracted oil from the acorns (they contain about 20% fat), by boiling and skimming...". Tozer UWP
  
• Fuel: "The Oaks are the most important firewood trees in North America, as they are excellent fuel. giving from 22 - 27 million Btu per cord." Tozer UWP
  
• Ink: Oak galls (swellings caused by insect larvae) were used for making ink, notably that used for printing money. Tozer UWP

References

• [E-flora-1]http://linnet.geog.ubc.ca/Atlas/Atlas.aspx?sciname=Quercus garryana&redblue=Both&lifeform=2, Accessed Jan 12, 2015
  
• [E-flora]http://linnet.geog.ubc.ca/Atlas/Atlas.aspx?sciname=Quercus robur&redblue=Both&lifeform=2, Accessed Jan 12, 2015
  
• [USDA]Quercus garryana, US Dept. of Agriculture, http://plants.usda.gov/core/profile?symbol=QUGA4
  
• [E-flora-2]Quercus robur, http://linnet.geog.ubc.ca/Atlas/Atlas.aspx?sciname=Quercus robur&redblue=Both&lifeform=2, Accessed Jan 12, 2015
  
• [GOERT] Garry Oak Ecosystem Recovery Team, http://www.goert.ca/propagation_guidelines/trees/quercus_garryana Accessed March 3, 2014
  
• [Herbs2000] Quercus robur, Accessed May 18, 2014
  
• [PFAF-1]Quercus garryana [http://www.pfaf.org/user/Plant.aspx?LatinName=Quercus+garryana], Accessed Jan 15, 2015
  
• [PFAF-2]http://www.pfaf.org/user/Plant.aspx?LatinName=Quercus+robur, Accessed Jan 12, 2015
  
• [Turner&Bell] The Ethnobotany of the Coast Salish Indians of Vancouver Island, Nancy Chapman Turner & Marcus A. M. Bell, Department of Biology, University of Victoria, Victoria, British Columbia, Canada. Submitted for publication 9 June 1969.