English Oak

English Oak

A genus of about 600 species of evergreen, semi-evergreen, and deciduous tress and a few shrubs, distributed throughout the northern hemisphere and in some montane regions of the southern hemisphere. Various species of oak are of particular importance in the lumber and tanning industries, and have a long history or use in shipbuilding. They are long-lived, and many are planted in parks and open spaces. The rigidly narrow Q. robur f. fastigiata is particularly useful for confined areas. In ancient times the oak was dedicated to Thor, the god of thunder. This gave rise to the belief that an oak tree could never be struck by lightning; hen the acorn-shaped wooden pulls attached to blind cords are thought to protect a house. The bark, galls, and acorns of various oaks are a major source of tannic acid. They contain up to 20 percent tannin, reaching 36-58 percent in Q. infectoria, an eastern Mediterranean species widely exploited by the pharmaceutical industry. Quercus alba (white oak) was important in native N American medicine as a remedy for diarrhea, wounds, and hemorrhoids. The Menominee and Potawatomi made syringes, using an animal bladder and hollow bone of a bird, for the injection of oak-bark infusion into the rectum. Quercus alba was adopted by settlers as a substitute for the common oak, and was listed as an astringent, tonic, and antiseptic in the U.S. Pharmacopoeia (1820-1916). Boiled in milk and water with the root of Verbana urticifolia (White Vervain), it makes a useful antidote to Rhus radicans (Poison Ivy).

Because of its high tannic acid content, oak bark was once an important ingredient used in the tanning of leather. Today it is used in powdered form to treat nosebleeds, in ointment form for hemorrhoids, and as a gargle for sore throats. Also, because of its anti-inflammatory and astringent properties, cold compresses made of oak bark tea are used for treating cuts and burns.

Large, deciduous tree with a broad crown, fissured bark, and very short-stalked, ovate-oblong leaves, to 14cm (5½in) long, which have lobed margins. Male flowers are borne in catkins; females in spikes of 1-5 in spring, followed by ovoid acorns, 4cm (1½in) long.

Common Name:
English Oak
Other Names:
Common Oak, Oak, Oak Bark, Pendunculate Oak, Tanner's Bark
Botanical Name:
Quercus robur
Native Location:
Europe to W Russia
Deep, well-drained soil in sun or partial shade. Remove lateral branches in late winter to maintain a clean trunk. Foliage may be damaged by mildew, oak phylloxera, chafer beetles, and caterpillars, particularly those of gypsy moths. Gall wasps cause the formation of galls on various parts of the tree, most commonly occuring on the leaves. Trees may be infected by honey fungus and various species of bracket fungus. Oak wilt is a major, usually lethal disease in some areas.
By seed sown when ripe; by grafting in mid-autumn or late winter.
Bark is removed in spring from trees 10-25 years old and dried for use in decoctions and liquid extracts.
Is slow growing, with red-purple young leaves, which mature to gray-purple.
Height: 10m (30ft)
Width: 10m (30ft)
(Golden Oak)

Is slow growing, and rounded, with golden young foliage that becomes yellow-green in summer.
Originated in Ghent in 1843.
Height: 10m (30ft)
Width: 10m (30ft)
f. fastigiata
(Cypress Oak)

Is very narrow, with upright branches.
Height: 25m (80ft)
Width: 5m (15ft)
25-35m (80-120ft)
25m (80ft)
Parts Used:
Bark, Leaf, Seed
A bitter, astringent, antiseptic herb that reduces inflammation and controls bleeding.
Medicinal Uses:
Internally for diarrhea, dysentery, hemorrhage, and prolapsed uterus or anus. Externally for hemorrhoids, vaginal discharge, sore throat, bleeding gums, minor injuries, dermatitis, weeping eczema, ringworm, ulcers, and varicose veins.
To treat eczema, genital and anal inflammation, gastrointestinal inflammation, diarrhea, cough, varicose veins, and rashes. Germany's Commission E has approved the use of oak to treat diarrhea, inflammation of the mouth and throat, cough, bronchitis, and skin inflammation.
Typical Dose:
A typical internal dose is approximately 1 gm of coarsely powdered bark mixed with 150 ml cold water, boiled for 2 minutes, strained and taken as a tea, up to three times a day.
Possible Side Effects:
Oak's side effects include nausea, vomiting, anorexia, and allergic reactions.
Drug Interactions:
Taking oak with these drugs may cause or increase kidney damage:
Etodolac, (Lodine, Utradol)
Ibuprofen, (Advil, Motrin)
Indomethacin, (Indocin, Novo-Methacin)
Ketoprofen, (Orudis, Rhodis)
Ketorolac, (Acular, Toradol)
Meloxicam, (MOBIC, Mobicox)
Metformin, (Glucophage, Riomet)
Methotrexate, (Rheumatrex, Trexall)
Miglitol, (Glyset)
Morphine Hydrochloride, (Morphine Hydrochloride)
Morphine Sulfate, (Kadian, MS Contin)
Naproxen, (Aleve, Naprosyn)
Nitrofurantoin, (Furadantin, Macrobid)
Ofloxacin, (Floxin, Ocuflox)
Penicillin, (Pfizerpen, Wycillin)
Piroxicam, (Feldene, Nu-Pirox)
Propoxyphene, (Darvon, Darvon-N)
Rifampin, (Rifadin, Rimactane)
Stavudine, (Zerit)
Sucralfate, (Carafate, Sulcrate)
Tramadol, (Ultram)
Valacyclovir, (Valtrex)
Valganciclovir, (Valcyte)
Vancomycin, (Vancocin)
Zidovudine, (Novo-AZT, Retrovir)
Taking oak with these drugs may interfere with the absorption of the drug:
Ferric Gluconate, (Ferrlecit)
Ferrous Fumarate, (Femiron, Feostat)
Ferrous Gluconate, (Fergon, Novo-Ferrogluc)
Ferrous Sulfate, (Feratab, Fer-Iron)
Ferrous Sulfate and Ascorbic Acid, (FeroGrad 500, Vitelle Irospan)
Iron-Dextran Complex, (Dexferrum, INFeD)
Morphine Hydrochloride, (Morphine Hydrochloride)
Morphine Sulfate, (Kadian, MS Contin)
Polysaccharide-Iron Complex, (Hytinic, Niferex)
Supplement Interactions:
  • The tannins in oak may cause the alkaloids in certain other herbs to separate and settle, increasing the risk of toxic reactions.
  • May cause the separation and settling out of iron salts when taken with Iron supplements.
Culinary Uses:
Acorns can be ground into flour and roasted as a coffee substitute.
Economic Uses:
Wood is traditionally used for making oak barrels that give a distinctive flavor to wine. Bark and galls are used in tanning and also in dyeing, the color produced being dependent on the mordant.
Not taken longer than four weeks at a time
Encyclopedia of Herbs by Deni Brown Copyright © 1995, 2001 Dorling Kindersley Limited Pg 339
The Essential Herb-Drug-Vitamin Interaction Guide by Geo. T. Grossberg,MD and Barry Fox,PhD Copyright©2007 Barry Fox,PhD. Pp.352-353