Tanbark Oak
Lithocarpus densiflorus

Family: Fagaceae

What it is like

Lithocarpus densiflorus is an evergreen Tree growing to 10 m (32ft) by 10 m (32ft) at a slow rate. See above for USDA hardiness. It is hardy to UK zone 7. It is in leaf all year, in flower from April to May. The species is monoecious (individual flowers are either male or female, but both sexes can be found on the same plant). Suitable for: light (sandy), medium (loamy) and heavy (clay) soils. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist soil.

Height (m): 10

Where it is found

Woody slopes below 1500 metres on fertile mountain slopes. It is found on a variety of soil types, but requires a humid atmosphere if it is to thrive.

South-western N. America - Oregon and California.

Conservation Status:

Countries/locations it is found in

How it is used

Food

Rating: 2

Seed - cooked. The seed was a staple food for several native North American Indian tribes. It contains bitter-tasting tannins and there are various ways of removing them. The fastest is by soaking the ground-up seed in hot water - if the water is changed at least once the tannins should be removed within 12 hours. Traditionally, the seeds were placed in a cloth bag and either buried in swampy ground or suspended in a running stream for a few months. Once the tannins have been removed, the seed is then dried, ground into a powder and can be used as a porridge or can be mixed with cereal flours in baking bread etc. It has a pleasant taste after it has been leached. The seed is up to 25mm long and wide. The seed is valued for its oil.

Oil: Oil

Seed: includes nuts, cereals, peas and beans.

Medicine

Rating: 1

The bark is very astringent. An infusion is used as a wash for face sores. The infusion can also be held in the mouth to tighten loose teeth.

Astringent: Produces contraction in living tissue, reducing the flow of secretions and discharges of blood, mucus, diarrhoea etc.

Odontalgic: Treats toothache (temporary measure only) and other problems of the teeth and gums.

Skin: Plants used in miscellaneous treatments for the skin.

Other

Rating:

The bark is exceedingly rich in tannin, yielding up to 29%. It has been used as a brown dye and also to preserve rope that is being used in water. Wood - hard, strong, close grained, brittle. It is not commercially important and is used mainly for fuel.

Dye: Plants that provide dyes.

Fuel: Usually wood, plant materials that have been mentioned as being a good fuel.

Oil: Vegetable oils have many uses, as lubricants, lighting, soap and paint making, waterproofing etc. This does not include the edible oils unless they are also mentioned as having other uses.

Preservative: For food, or for treating wood, ropes etc.

Tannin: An astringent substance obtaied from plants, it is used medicinally, as a dye and mordant, stabilizer in pesticide etc.

Wood: A list of the trees and shrubs that are noted for having useful wood.

How it is grown

Prefers a deep fertile soil with medium drainage. Perfectly hardy at Kew, trees produced seed at Kew in the very hot summer of 1989. A slow-growing tree in the wild, living up to 300 - 350 years old. Plants usually flower in the spring and sometimes again in the autumn. The seeds take two seasons to ripen. Prolific crops are usually produced every other year in the wild.

Propagating it: The seed is best sown as soon as it is ripe in the autumn in a cold frame. It needs to be protected from mice, squirrels and other seed eaters. The seed has a short viability but can be stored for a few months if kept cool and slightly damp - the salad compartment of a fridge is a good storage place. Germination takes place in the winter or early spring. When they are large enough to handle, prick the seedlings out into individual pots. If the plants are 15cm or more tall by the summer they can be planted out into their permanent positions. Give them a good weed-excluding mulch and some protection from the cold for their first couple of years outdoors. If growth is not sufficient then grow them on in the greenhouse for their first winter and plant them out into their permanent positions in late spring or early summer, after the last expected frosts.

Best place to grow: Woodland Garden Canopy;

Habit: Tree

Hardiness: 6-9

Growth: Slow

Soil: Light (sandy), medium, heavy (clay)

Shade: Semi-shade, no shade

Moisture: Moist

Things to keep in mind

Its other names

Local names

Synonyms

Pasania densiflora. Quercus densiflora.