A nut in botany is a simple dry fruit with one seed (rarely two) in which the ovary wall becomes very hard (stony or woody) at maturity, and where the seed remains attached or fused with the ovary wall.
So, hazelnuts, hickories, chestnuts and acorns are true nuts. That leaves just about everything we call a nut as a non-nut, typically a seed:
- Almonds, pecans and walnuts are the edible seeds of drupe fruits — the leathery “flesh” is removed at harvest.
- Brazil nut is the seed from a capsule.
- Candlenut (used for oil) is a seed.
- Cashew nut is a seed.
- Horse-chestnut is an inedible capsule.
- Macadamia nut is a creamy white kernel (Macadamia integrifolia).
- Malabar chestnut
- Peanut is a legume.
- Pine nut is the seed of several species of pine (coniferous trees).
- Pistachio nut is the seed of a thin-shelled drupe.
Would you like some roasted drupe-fruit seeds?