Walnut
Juglans regia
Family · Juglandaceae · Harmless
The walnut tree, planted on farms and stream margins across the country and gone feral in many valleys. Almost nothing grows under a walnut, and that is no accident: the roots release a compound that stops competition.
Streams and ditches · Fields and pasture · Oak woods · Town and roadside
Also known asEnglish walnut, Persian walnut
How to tell it
A compound leaf of five to nine large, smooth-edged leaflets, with a strong characteristic smell when crushed. Smooth grey bark when young, cracked with age. A round green fruit that splits and releases the nut inside.
What it is confused with
Tree of heaven
Ailanthus altissima
Both have a large compound leaf and a strong smell. Walnut has five to nine smooth-edged leaflets and a pleasant smell; tree of heaven has twenty or more leaflets with two glandular teeth at the base and smells of rancid butter.
Open sheet →What it is for
The nut, and the green husk that stains hands brown for a week and was a dye and wood varnish. The leaves were an infusion and a home insecticide. The compound it releases is called juglone, and it is why you do not plant a vegetable garden under a walnut.
Traditionally used as food. This is not permission to eat it.
With documented traditional uses. Not a therapeutic indication and not a dose.