Nuts – real and “fake”
Nuts are tasty and healthy. But what exactly are nuts, and why – at least in botany – is a distinction made between real and false nuts? Characteristic for a real nut are three woody fruit wall layers which enclose the nut fruit. What we eat is the seed of the fruit, which is sold as a nut. Hazelnuts, walnuts, beechnuts and sweet chestnuts belong to the real nuts.
So-called “false” nuts are those that are commonly referred to as such, but are actually legumes, stone fruits or capsule fruits.
Pulses and stone fruits
The peanut is a legume and therefore related to peas and beans. Almonds, pistachios and pecans are drupes and therefore in a group with peaches, plums or olives. The characteristic feature is that only the inner fruit wall, which is surrounded by the fruit flesh, is lignified. So here we don’t eat the seed, but the kernel. Also the cashew nut belongs to the stone fruits. But it is a special case, because the kernel is not surrounded by the flesh, but hangs outside the cashew apple.
The Brazil nut in turn belongs neither to the nut, nor to the stone or legume fruits, but is a capsule fruit. Here, too, the flesh of the fruit is lignified and contains the seeds that we eat. The “nuts” grow in large fruit capsules on the tree.