Anacardium is a tropical genus of trees and plants native to the Americas. The most famous representative of this genus is A. occidentale, the cashew tree, a plant grown commercially for its seeds. Cashews can also be found growing in the wild around their native Brazil, and are sometimes grown by individual gardeners interested in maintaining a cashew tree or a small stand of them. Nurseries in regions with hospitable climates may carry seedlings or can order them if customers request them.
This genus is placed in the cashew or sumac family, known as Anacardiaceae. Anacardium species vary widely in height and appearance, depending on the species. All have adapted to live in the warm, humid, moist environment of the tropics. They tend to prefer rich, well-drained soil worked with ample organic material to mimic the conditions found in tropical forests. Some prefer partial shade and filtered sunlight, while other species may be designed to live in full sun.
As with some other members of the cashew family, Anacardium species produce proteins known to be irritants and toxins. Contact with the sap can cause skin irritation and some people experience violent allergic reactions to the sap, as well as the fruit of these trees. In some cases, these allergies can be life threatening. People with allergies to cashews may not necessarily be allergic to other tree nuts, as the proteins involved are different.
In the case of the cashew tree, the plant produces large, hanging drupes. Each drupe contains a single seed that must be roasted or steamed before use to neutralize the dangerous proteins. In addition to the seed, the plant produces a large, fleshy appendage known as a cashew apple. Cashew apples are eaten in some regions of the world and are considered a byproduct of the commercial cashew trade.
People living in United States Department of Agriculture (USDA) zones nine through 11 can cultivate cashew trees. Full sun will be needed for an Anacardium and it is also necessary to plant the tree in an area with some room to grow, as the canopy of the tree can sprawl quite far as the tree matures. Individuals with a history of allergic reactions to poison sumac may want to skip cultivation of these flowering plants, as the irritants involved are the same. It is also important to keep children and pets away from the colorful, appealing, and toxic Anacardium drupes.