Quercus aliena

What to Eat

Edible parts: Seeds, Nuts

The seed, about 25mm long, must be cooked before use. Once dried and ground into a powder, it works well as a stew thickener or can be blended with cereals for bread-making. Bitter tannins are present and need to be removed by thoroughly washing the seed in running water, though this also leaches out some minerals. Whole seeds can be leached, but this may take several days or weeks — a traditional method was to wrap them in a cloth bag and place them in a running stream. Grinding the seed to a powder first speeds up the process considerably. A simple taste test confirms when enough tannin has been removed. Another traditional approach was to bury the seed in boggy ground over winter; the germinating seed dug up in spring would have lost most of its astringency. The roasted seed also serves as a coffee substitute.

Where to Find It

It is a temperate plant. In China it grows in mixed forest between 100-2700 m altitude.

Asia, Australia, China, Japan, Korea, SE Asia, Thailand,

How to Identify

A tree. It grows to 30 m tall. It loses its leaves during the year. The leaf stalk is 1-1.3 cm long and the leaf blade is narrowly oval. It is 10-20 cm long by 5-14 cm wide. The base is wedge shaped or rounded. It tapers to a short tip. The female flowering shoot is in the axils of leaves on young shoots. The nut is 1.7-2.5 cm long by 1.3-1.8 cm wide. The cup encloses half the nut.

How to Grow

Prefers a good deep fertile loam which can be on the stiff side. Lime tolerant. Young plants tolerate reasonable levels of side shade. Tolerates moderate exposure, surviving well but being somewhat stunted. Prefers warmer summers than are usually experienced in Britain, trees often grow poorly in this country and fail to properly ripen their wood resulting in frost damage overwinter. Intolerant of root disturbance, trees should be planted in their permanent positions whilst young. The seed ripens in its first year. Hybridizes freely with other members of the genus. Plants in this genus are notably resistant to honey fungus.

Propagation: Seed loses viability quickly if allowed to dry out. It can be stored moist and cool over winter, but is best sown as soon as it ripens in an outdoor seed bed with protection against mice and squirrels. Small quantities can be sown in deep pots in a cold frame. Because plants develop a deep taproot, they should be moved to their permanent positions as soon as possible — seed sown in situ produces the best trees. Do not leave trees in a nursery bed for more than two growing seasons, as they transplant very poorly after that point.

Medicinal Uses

Any galls that form on the tree are strongly astringent and have been used medicinally to treat haemorrhages, chronic diarrhoea, and dysentery.

Other Uses

Partially decayed oak leaves used as a mulch around plants will repel slugs, grubs, and similar pests — though fresh leaves should be avoided as they can inhibit plant growth. Oak galls, produced when insect larvae develop inside growths on the tree, are a rich source of tannin once the insects have pupated and left. This tannin can also be used as a dyestuff. The wood is of local value and is used mainly for boat building.

Quercus aliena, the galcham oak or oriental white oak, is a species of oak in the family Fagaceae, in the white oak section Quercus.

Other Information

It is a cultivated food plant.

Notes

There are about 600 Quercus species.

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