Habitat
Type: woods, often pure
Distribution: throughout northern hemisphere
Prefers: base soil

General
Growth type: tree
Cycle: deciduous
Height: up to 35 meters
Other: shady; bare ground below

Leaf
Shape: pointed oval
Texture: ribbed
Arrangement: alternate
Edge: toothed
Other: bright green in spring

Trunk
Colour: pale grey
Texture: smooth

Flower
Arrangement: pairs
When: April to May with leaves
Colour:

Seed
Shape: three-sided
Colour: red-brown
Size: small
Casing: prickly husk, four lobes open when ripe
Other: not every year, 3-8 year cycle

May be toxic if it contains tannin, and is consumed in large quantities. Tannin binds with protein, can interfere with iron absorption and can cause gastric pain, irritation to organs and liver damage. It is bitter and astringent and colours water dark. It may be reduced or removed by leaching in several changes of water, until it runs clear (not brown). Baking soda added to the water may speed up the process. Tannin breaks down with time.

April to May
all year
September and October

Parts with black and white icons are for non-culinary use

Flavour
Rating and Description:
mild
nutty

How to Consume
best young, raw; leaf curd
raw, oil

Special preparation
Difficult to peel, as very fiddly. Extract oil by crushing whole nut (without outer casing) and press the pulp. As some seeds may be mouldy in the shell, it is best to test them by putting them in water. Fertile, i.e. viable seeds will sink.

Nutrition
fat, protein

Used as ...
food
food, condiment

Action:
(bark) antiseptic, antitussive, expectorant, febrifuge, odontalgic

May treat:
(bark) skin

(trunk) timber

Collection
ripe seeds fall to the ground; good mast years rotate on a three or more year cycle

Plant parts:
leaf
stem or trunk
sap
root, bulb, tuber and other below ground parts
flower
fruit
seed

Parts with black and white icons in the availability section are for non-culinary use

Use:
culinary use
medicinal use
household use

Other:
caution

Glossary of Medicinal Terms and Nutritive Substances

• antiseptic: prevents putrefaction (applied to wounds)
• antitussive: prevents or relieves coughing
• expectorant: removes excess amount of mucus from respiratory system (see also decongestant)
• febrifuge: reduces fever; use only for dangerously high temperature; a raised temperature is the body's way of burning up the pathogen
• odontalgic: treats toothache (temporarily) and other problems of the teeth and gums