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Useful Temperate Plants

Quercus glauca

Thunb.

Fagaceae

+ Synonyms

Cyclobalanopsis amamiana (Hatus.) Masam.

Cyclobalanopsis glauca (Thunb.) Oerst.

Cyclobalanopsis globosa T.P.Lin & T.S.Liu

Cyclobalanopsis repandifolia (J.C.Liao) J.C.Liao

Cyclobalanopsis sasakii (Kaneh.) Kudô & Masam.

Cyclobalanopsis vibrayeana (Franch. & Sav.) Schottky

Perytis glauca (Thunb.) Raf.

Quercus acuta bambusifolia G.Nicholson

Quercus amamiana Hatus.

Quercus bambusifolia Fortune

Quercus blakei vaniotii (H.Lév.) Chun

Quercus dentosa Lindl. ex Wall.

Quercus globosa (T.P.Lin & T.S.Liu) J.C.Liao

Quercus ichangensis Nakai ex A.Camus

Quercus lacera Blume

Quercus laxiflora Lindl. ex Wall.

Quercus longipes Hu

Quercus lotungensis Chun & W.C.Ko

Quercus matasii Siebold

Quercus repandifolia J.C.Liao

Quercus sasakii Kaneh.

Quercus tranninhensis Hickel & A.Camus

Quercus vaniotii H.Lév.

Quercus vibrayeana Franch. & Sav.

Common Name: Blue Japanese Oak

No Image.

General Information

Quercus glauca is an evergreen tree with a dense, round or oval crown; it can grow up to 15 metres tall[
1213
Title
Southern Trees Fact Sheets
Publication
 
Author
Gilman E.F.
Website
http://edis.ifas.ufl.edu/department_envhort-trees
Publisher
University of Florida, IFAS Extension
Year
0
ISBN
 
Description
A series of fact sheets on trees that can be grown in Florida. They can be downloaded from the Internet
].
The tree is harvested from the wild for mainly local use as a food, medicine and source of materials. The wood is of verygood quality and is harvested on a commercial basis in Japan. The tree is valued as an ornamental, often being grown as a street tree.

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[
293
Title
Poisonous Plants of North Carolina
Publication
 
Author
 
Website
http://www.ces.ncsu.edu/depts/hort/consumer/poison/poison.htm
Publisher
 
Year
0
ISBN
 
Description
An excellent concise but comprehensive guide to toxic plants that grow in N. Carolina. It lists even those plants that are of very low toxicity, including several well-known food plants such as carrots and potatoes.
].

Botanical References

11
Title
Trees and Shrubs Hardy in Great Britain. Vol 1 - 4 and Supplement.
Publication
 
Author
Bean. W.
Publisher
Murray
Year
1981
ISBN
-
Description
A classic with a wealth of information on the plants, but poor on pictures.
,
58
Title
Flora of Japan. (English translation)
Publication
 
Author
Ohwi. G.
Publisher
Smithsonian Institution
Year
1965
ISBN
-
Description
The standard work. Brilliant, but not for the casual reader.
,
200
Title
The New RHS Dictionary of Gardening. 1992.
Publication
 
Author
Huxley. A.
Publisher
MacMillan Press
Year
1992
ISBN
0-333-47494-5
Description
Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.

Range

E. Asia - China, Japan, Himalayas.

Habitat

Moist forests and ravines, not gregarious, 800 - 3000 metres from Pakistan to S.W. China[
51
Title
Flowers of the Himalayas.
Publication
 
Author
Polunin. O. and Stainton. A.
Publisher
Oxford Universtiy Press
Year
1984
ISBN
-
Description
A very readable and good pocket guide (if you have a very large pocket!) to many of the wild plants in the Himalayas. Gives many examples of plant uses.
]. Shady valleys[
158
Title
Forest Flora of Chakrata, Dehra Dun and Saharanpur.
Publication
 
Author
Gupta. B. L.
Publisher
Forest Research Institute Press
Year
1945
ISBN
-
Description
A good flora for the middle Himalayan forests, sparsly illustrated. Not really for the casual reader.
].

Properties

Edibility Rating *  *  *
Medicinal Rating *  *
Other Uses Rating *  *
HabitEvergreen Tree
Height10.00 m
Growth RateSlow
PollinatorsWind
Cultivation StatusWild

Cultivation Details

Quercus glauca is not very cold-hardy, tolerating short-lived temperatures down to around -10°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[
11
Title
Trees and Shrubs Hardy in Great Britain. Vol 1 - 4 and Supplement.
Publication
 
Author
Bean. W.
Publisher
Murray
Year
1981
ISBN
-
Description
A classic with a wealth of information on the plants, but poor on pictures.
,
200
Title
The New RHS Dictionary of Gardening. 1992.
Publication
 
Author
Huxley. A.
Publisher
MacMillan Press
Year
1992
ISBN
0-333-47494-5
Description
Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
].
Prefers a good deep fertile loam which can be on the stiff side[
1
Title
RHS Dictionary of Plants plus Supplement. 1956
Publication
 
Author
F. Chittendon.
Publisher
Oxford University Press
Year
1951
ISBN
-
Description
Comprehensive listing of species and how to grow them. Somewhat outdated, it has been replaced in 1992 by a new dictionary (see [200]).
,
11
Title
Trees and Shrubs Hardy in Great Britain. Vol 1 - 4 and Supplement.
Publication
 
Author
Bean. W.
Publisher
Murray
Year
1981
ISBN
-
Description
A classic with a wealth of information on the plants, but poor on pictures.
]. Prefers a well-drained soil, but can tolerate poorly drained, heavy clay soils[
1213
Title
Southern Trees Fact Sheets
Publication
 
Author
Gilman E.F.
Website
http://edis.ifas.ufl.edu/department_envhort-trees
Publisher
University of Florida, IFAS Extension
Year
0
ISBN
 
Description
A series of fact sheets on trees that can be grown in Florida. They can be downloaded from the Internet
]. Young plants tolerate reasonable levels of side shade[
200
Title
The New RHS Dictionary of Gardening. 1992.
Publication
 
Author
Huxley. A.
Publisher
MacMillan Press
Year
1992
ISBN
0-333-47494-5
Description
Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
]. Tolerates moderate exposure, surviving well but being somewhat stunted[
200
Title
The New RHS Dictionary of Gardening. 1992.
Publication
 
Author
Huxley. A.
Publisher
MacMillan Press
Year
1992
ISBN
0-333-47494-5
Description
Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
]. Established plants are very drought tolerant[
1213
Title
Southern Trees Fact Sheets
Publication
 
Author
Gilman E.F.
Website
http://edis.ifas.ufl.edu/department_envhort-trees
Publisher
University of Florida, IFAS Extension
Year
0
ISBN
 
Description
A series of fact sheets on trees that can be grown in Florida. They can be downloaded from the Internet
].
A slow-growing plant[
1213
Title
Southern Trees Fact Sheets
Publication
 
Author
Gilman E.F.
Website
http://edis.ifas.ufl.edu/department_envhort-trees
Publisher
University of Florida, IFAS Extension
Year
0
ISBN
 
Description
A series of fact sheets on trees that can be grown in Florida. They can be downloaded from the Internet
].
A polymorphic species[
11
Title
Trees and Shrubs Hardy in Great Britain. Vol 1 - 4 and Supplement.
Publication
 
Author
Bean. W.
Publisher
Murray
Year
1981
ISBN
-
Description
A classic with a wealth of information on the plants, but poor on pictures.
]. The seed ripens in its first year[
200
Title
The New RHS Dictionary of Gardening. 1992.
Publication
 
Author
Huxley. A.
Publisher
MacMillan Press
Year
1992
ISBN
0-333-47494-5
Description
Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
].
Seedlings soon develop a taproot and become intolerant of root disturbance, they should be planted into their permanent positions whilst young[
11
Title
Trees and Shrubs Hardy in Great Britain. Vol 1 - 4 and Supplement.
Publication
 
Author
Bean. W.
Publisher
Murray
Year
1981
ISBN
-
Description
A classic with a wealth of information on the plants, but poor on pictures.
].
Hybridizes freely with other members of the genus[
200
Title
The New RHS Dictionary of Gardening. 1992.
Publication
 
Author
Huxley. A.
Publisher
MacMillan Press
Year
1992
ISBN
0-333-47494-5
Description
Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
].
Plants in this genus are notably resistant to honey fungus[
200
Title
The New RHS Dictionary of Gardening. 1992.
Publication
 
Author
Huxley. A.
Publisher
MacMillan Press
Year
1992
ISBN
0-333-47494-5
Description
Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
].

Edible Uses

Seed - raw or cooked[
61
Title
A Dictionary of Plants Used by Man.
Publication
 
Author
Usher. G.
Publisher
Constable
Year
1974
ISBN
0094579202
Description
Forget the sexist title, this is one of the best books on the subject. Lists a very extensive range of useful plants from around the world with very brief details of the uses. Not for the casual reader.
,
105
Title
Tanaka's Cyclopedia of Edible Plants of the World.
Publication
 
Author
Tanaka. T. & Nakao S.
Publisher
Keigaku Publishing; Tokyo
Year
1976
ISBN
-
Description
The most comprehensive list of edible plants I've come across. Only the briefest entry for each species, though, and some of the entries are more than a little dubious. Not for the casual reader.
,
865
Title
Chinese Economic Trees
Publication
 
Author
Woon Young Chun
Website
http://www.biodiversitylibrary.org
Publisher
Commercial Press; Shanghai.
Year
1921
ISBN
 
Description
Brief details of many of the Chinese trees with economic importance. It can be downloaded from the Internet.
]. A sweet taste[
178
Title
Chinese Materia Medica.
Publication
 
Author
Stuart. Rev. G. A.
Publisher
Taipei. Southern Materials Centre
Year
1911
ISBN
-
Description
A translation of an ancient Chinese herbal. Fascinating.
]. The seed is about 15mm long[
200
Title
The New RHS Dictionary of Gardening. 1992.
Publication
 
Author
Huxley. A.
Publisher
MacMillan Press
Year
1992
ISBN
0-333-47494-5
Description
Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
].
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.

Leaves - cooked. A famine food[
179
Title
Famine Foods listed in the Chiu-Huang Pen-ts'ao.
Publication
 
Author
Reid. B. E.
Publisher
Southern Materials Centre; Taipei
Year
1977
ISBN
-
Description
A translation of an ancient Chinese book on edible wild foods. Fascinating.
].

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[
4
Title
A Modern Herbal.
Publication
 
Author
Grieve.
Publisher
Penguin
Year
1984
ISBN
0-14-046-440-9
Description
Not so modern (1930's?) but lots of information, mainly temperate plants.
]. Extracts of the plant can be added to ointments and used for the healing of cuts[
4
Title
A Modern Herbal.
Publication
 
Author
Grieve.
Publisher
Penguin
Year
1984
ISBN
0-14-046-440-9
Description
Not so modern (1930's?) but lots of information, mainly temperate plants.
,
1231
Title
Antibacterial and Antifungal Activities of Some Quercus Species Growing in Turkey
Publication
FABAD J. Pharm. Sci., 32, 127-130, 2007
Author
Didem Söhretoğlu; Melike Ekizoğlu; Ekrem Kiliç; M. Koray Sak
Publisher
 
Year
2007
ISBN
 
Description
 
].

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[
20
Title
Companion Planting for Successful Gardening.
Publication
 
Author
Riotte. L.
Publisher
Garden Way, Vermont, USA.
Year
1978
ISBN
0-88266-064-0
Description
Fairly good.
,
K
Title
Plants for a Future
Author
Ken Fern
Description
Notes from observations, tasting etc at Plants For A Future and on field trips.
]..

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[
4
Title
A Modern Herbal.
Publication
 
Author
Grieve.
Publisher
Penguin
Year
1984
ISBN
0-14-046-440-9
Description
Not so modern (1930's?) but lots of information, mainly temperate plants.
,
331
Title
Flora of Guatemala
Publication
 
Author
Standley P.C. & J. A. Steyermark
Website
http://www.archive.org/
Publisher
 
Year
1946 - 1976
ISBN
 
Description
A superb reference, though somewhat dated. Gives lots of plant uses as well as information on plant habit and habitat. The entire flora (13 volumes) can now be downloaded from http://www.archive.org/
].
The bark of oak trees is also usually rich in tannins and can be used as a dyestuff and for waterproofing rope[
331
Title
Flora of Guatemala
Publication
 
Author
Standley P.C. & J. A. Steyermark
Website
http://www.archive.org/
Publisher
 
Year
1946 - 1976
ISBN
 
Description
A superb reference, though somewhat dated. Gives lots of plant uses as well as information on plant habit and habitat. The entire flora (13 volumes) can now be downloaded from http://www.archive.org/
,
K
Title
Plants for a Future
Author
Ken Fern
Description
Notes from observations, tasting etc at Plants For A Future and on field trips.
].

The heartwood is grey or greyish-brown; it is clearly demarcated from the lighter-coloured sapwood. The wood is tough, very hard, takes a good polish but warps during seasoning. It is used for general construction and fuel[
46
Title
Dictionary of Economic Plants.
Publication
 
Author
Uphof. J. C. Th.
Publisher
Weinheim
Year
1959
ISBN
-
Description
An excellent and very comprehensive guide but it only gives very short descriptions of the uses without any details of how to utilize the plants. Not for the casual reader.
,
51
Title
Flowers of the Himalayas.
Publication
 
Author
Polunin. O. and Stainton. A.
Publisher
Oxford Universtiy Press
Year
1984
ISBN
-
Description
A very readable and good pocket guide (if you have a very large pocket!) to many of the wild plants in the Himalayas. Gives many examples of plant uses.
,
61
Title
A Dictionary of Plants Used by Man.
Publication
 
Author
Usher. G.
Publisher
Constable
Year
1974
ISBN
0094579202
Description
Forget the sexist title, this is one of the best books on the subject. Lists a very extensive range of useful plants from around the world with very brief details of the uses. Not for the casual reader.
,
158
Title
Forest Flora of Chakrata, Dehra Dun and Saharanpur.
Publication
 
Author
Gupta. B. L.
Publisher
Forest Research Institute Press
Year
1945
ISBN
-
Description
A good flora for the middle Himalayan forests, sparsly illustrated. Not really for the casual reader.
,
272
Title
Plants and People of Nepal
Publication
 
Author
Manandhar. N. P.
Publisher
Timber Press. Oregon.
Year
2002
ISBN
0-88192-527-6
Description
Excellent book, covering over 1,500 species of useful plants from Nepal together with information on the geography and peoples of Nepal. Good descriptions of the plants with terse notes on their uses.
]. The wood is highly valued and widely utilized in Japan where it is used for a wide variety of purposes but is especially valued for its strength and hardness, being used for agricultural implements, the handles of spears, rudders of boats etc[
1220
Title
Forestry of Japan
Publication
 
Author
Norinsho. Sanrinkyoku
Website
http://www.biodiversitylibrary.org/bibliography/45231#/summary
Publisher
Bureau of Forestry, Dept of Agriculture and Commerce, Japan
Year
1910
ISBN
 
Description
Rather dated, but a lot of information about the forestry products of Japan
].
The wood is used as a fuel[
46
Title
Dictionary of Economic Plants.
Publication
 
Author
Uphof. J. C. Th.
Publisher
Weinheim
Year
1959
ISBN
-
Description
An excellent and very comprehensive guide but it only gives very short descriptions of the uses without any details of how to utilize the plants. Not for the casual reader.
,
51
Title
Flowers of the Himalayas.
Publication
 
Author
Polunin. O. and Stainton. A.
Publisher
Oxford Universtiy Press
Year
1984
ISBN
-
Description
A very readable and good pocket guide (if you have a very large pocket!) to many of the wild plants in the Himalayas. Gives many examples of plant uses.
,
61
Title
A Dictionary of Plants Used by Man.
Publication
 
Author
Usher. G.
Publisher
Constable
Year
1974
ISBN
0094579202
Description
Forget the sexist title, this is one of the best books on the subject. Lists a very extensive range of useful plants from around the world with very brief details of the uses. Not for the casual reader.
,
158
Title
Forest Flora of Chakrata, Dehra Dun and Saharanpur.
Publication
 
Author
Gupta. B. L.
Publisher
Forest Research Institute Press
Year
1945
ISBN
-
Description
A good flora for the middle Himalayan forests, sparsly illustrated. Not really for the casual reader.
,
272
Title
Plants and People of Nepal
Publication
 
Author
Manandhar. N. P.
Publisher
Timber Press. Oregon.
Year
2002
ISBN
0-88192-527-6
Description
Excellent book, covering over 1,500 species of useful plants from Nepal together with information on the geography and peoples of Nepal. Good descriptions of the plants with terse notes on their uses.
].

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
Title
Trees and Shrubs Hardy in Great Britain. Vol 1 - 4 and Supplement.
Publication
 
Author
Bean. W.
Publisher
Murray
Year
1981
ISBN
-
Description
A classic with a wealth of information on the plants, but poor on pictures.
]. Trees should not be left in a nursery bed for more than 2 growing seasons without being moved or they will transplant very badly.

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