When it comes to nuts and seeds, it’s easy to get confused by name, size and other factors. Here’s our guide to work out which is which, along with some handy examples.
What is a nut?
The botanical definition of a nut in its simplest form is a seed contained in a hard shell which doesn’t naturally open to release the seed when it matures.
The culinary definition of a nut is much simpler and incorporates a whole range of edible plant parts. It’s often considered to be any edible kernel surrounded by a shell.
What is a seed?
A seed is a mature fertilised ovule of a plant which consists of three parts:
embryo – where the new plant forms if subject to the right conditions
endosperm - a food store
seed coat – a protective covering.
A seed may also go by the name of kernel, pip, pit or stone depending on its source.
To confuse matters, a nut can also be a seed. But a seed by definition is not a nut.
Seeds we commonly think of as nuts
Despite the name, peanuts are not really nuts - at least not in the botanical sense. The peanut grows underground, in a pod like peas and lentils. This means it is not classified as a nut but as a legume. This is reflected in the ‘pea’ part of the name.
The botanical definition means many foods we call nuts are actually seeds! Foods that fall into this trap include:
The term tree nut is often used to cover this group of seeds.
Nuts we commonly think of as seeds
One of the most common nuts to be mistaken for a seed is beech mast, produced by the beech tree. Prickly four lobed cases protect one or two triangular nuts which are an important food source for mice, voles, squirrels and birds.
The hornbeam tree also produces nuts which masquerade as seeds. Female catkins develop into papery, green winged fruits, known as samaras. At the base of each leafy bract is a small nut about 3-6 mm long.
Nuts and seeds of other UK trees
Thankfully, other tree nuts and seeds aren’t so tricky to identify! Here’s what to expect from some of our other most common trees.
Alder: seeds grow inside the tiny cone-like fruits. Alder often grows close to water and its seeds are designed so they can float along to a new home.
Ash: hanging together in bunches, the long, narrow seeds of ash are also known as keys.