Cyclobalanopsis gemelliflora (Blume) Oerst.
Cyclobalanopsis horsfieldii (Miq.) Oerst.
Cyclobalanopsis merkusii (Endl.) Oerst.
Cyclobalanopsis turbinata (Blume) Schottky
Quercus crassilamellata (Gamble) A.Camus
Quercus horsfieldii Miq.
Quercus lineata merkusii (Endl.) Wenz.
Quercus merkusii Endl.
Quercus semiserrata mannii Hook.f.
Quercus turbinata Blume
Quercus gemelliflora is an evergreen tree that can grow up to 30 metres tall. The bole can be up to 60cm in diameter[
This is one of several timber-bearing species in the genus Quercus that is harvested from the wild on a commercial basis and traded under the name Mempening[
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[
Southeast Asia - Malaysia, Indonesia
Found on red sandy clay overlying sandstone or granite or on ultrabasic soils, growing in mixed dipterocarp forest to montane forest, usually near streams; at elevations up to 2,600 metres[
Quercus species generally grow well in a sunny position, though young plants usually tolerate reasonable levels of side shade[
]. They usually prefer a good deep fertile loam which can be on the stiff side[
]. They are also often tolerant of moderate exposure, surviving well but being somewhat stunted[
Seedlings soon develop a taproot and become intolerant of root disturbance, they should be planted into their permanent positions whilst young[
Plants can flower and produce seed all year round in their native environment[
Most Quercus species hybridize freely with other members of the genus[
Plants in this genus are notably resistant to honey fungus[
The ovoid, conical or cylindrical seed is 20 - 55mm long and 20 - 25mm wide[
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 of many Quercus species has been used as a coffee substitute.
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[
The bark of most species is rich in tannins and can be used as a dye and preservative for ropes etc[
The sapwood is white[
The heartwood is yellow-brown, red-brown or dark red-brown; it is not always clearly demarcated from the lighter-coloured sapwood. The texture is rather coarse and uneven; the grain fairly straight but sometimes interlocked; there is a true oak-line silver figure prominent on the radial surface. The wood is strong to very strong; hard to very hard; moderately heavy to heavy; moderately durable and very difficult to treat. It seasons fairly slowly, without any defects except for some staining, slight bowing and end-checking; shrinkage is high. It is easy to saw when green, but slightly difficult to work when dried; planing is easy and the planed surface is smooth; turned wood has a rough surface when finished. Nailing properties are poor.
A medium hardwood, it is suitable for medium to heavy construction under cover, furniture making, interior finishing, panelling, parquet flooring etc[
]. It is used locally for purposes such as fence post, mining props, shingles, boat building, and for making tool handles, rice pounder, poles for carts etc[
The wood makes a good fuel and can be used to make charcoal[
Seed - it quickly loses viability if it is allowed to dry out. It can be stored moist and cool, 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.