Every cashew grows out of the bottom of a fruit called a cashew apple.

A cashew tree produces a distinctive pair: a fleshy red or yellow cashew apple and a curved shell-bearing fruit attached at its end. Inside that shell is the edible seed sold as a cashew nut. The familiar snack is therefore only one part of a much larger structure.

The cashew apple develops from the enlarged stalk associated with the flower and fruit. It is commonly called a false fruit or accessory fruit because its edible tissue does not come mainly from the ovary. The attached kidney-shaped structure is the botanical fruit containing the seed.

The shell contains an irritating liquid that must be managed during processing. This is why cashews in shops are normally sold without their natural shells. The important safety distinction is between commercially processed kernels and freshly harvested shell-bearing fruits, not simply between a pale cashew and a browned one.

The cashew, Anacardium occidentale, is native to northeastern Brazil. Britannica describes its movement to East Africa and India through Portuguese activity in the late sixteenth century. Its later importance in those regions can make its American origin easy to overlook when the nut appears in Asian dishes.

Both parts of the crop can be useful. Cashew apples are eaten locally or processed into drinks and other foods, while the kernels enter a large international trade. The fleshy apple is more perishable than a processed nut, helping explain why shoppers far from growing regions often know only the seed.

Processing separates the valuable kernel from the difficult shell. Methods can involve heat treatment, shelling and removal of the skin around the kernel. Procedures differ, so saying every cashew is roasted is too absolute. The accurate general point is that commercial kernels have undergone controlled processing before reaching consumers.

The tree belongs to the sumac family, Anacardiaceae, which also includes plants associated with irritating compounds. That relationship helps put the shell hazard in context, but it should not become a blanket claim that a properly processed edible kernel is poisonous. The plant part and the way it has been handled matter.

A package labeled raw generally distinguishes its kernels from nuts given a final roasting for flavor and texture. It does not necessarily mean the kernels were pulled from untreated shells without any processing. Consumer language about roasting and industrial language about shell treatment describe different stages.

Do not attempt to open freshly harvested cashew fruits using ordinary snack-nut methods. Contact with shell liquid can cause injury, and improvised roasting can create additional exposure. Buy food-grade kernels from established suppliers. People with cashew allergy must still avoid cashews according to their clinical advice, regardless of whether the package says raw or roasted.

A photograph of a cashew still attached to its apple reveals two structures that supermarket packaging normally separates. The fleshy apple and the shell-bearing true fruit have different botanical origins and different uses. Calling the whole arrangement a nut growing outside an apple is memorable, but leaves that anatomy unresolved.