Almond
The meat found inside the pit of a dry fruit related to peaches, the almond is delicate and fragrant. It has a pointed, oval shape and a smooth texture that lends itself well to elegant presentations.

Brazil Nut
Enclosed in a dark, hard, roughly textured shell shaped like a small orange segment, Brazil nuts taste somewhat like the meat of a coconut. They are the seeds of 250-foot-high trees that grow only in tropical regions of South America and require great labor to harvest. They are best eaten as snacks or used in desserts.

Candlenut
Looking like large macadamias and sold packaged in Asian markets, these nuts of a native Malaysian bush are traditionally ground and mixed into the curries and spice pastes of the region to add body and richness. Macadamia or Brazil nuts or cashews may be substituted. The nut's name comes from the fact that Malaysian natives sometimes used the ground nuts as candles.

Cashew
A smooth, kidney-shaped nut from a tree native to Africa and India, cashews are always sold removed from their hard shell and caustic lining. Most commonly eaten whole as a snack, cashews also make excellent nut butter.

Chestnut
Known as marrons in France, chestnuts are large and wrinkled and have a smooth, shiny, mahogany-colored shell shaped like a turban slightly flattened on one side. Unlike other nuts, they contain a high amount of starch and little oil. Often treated as a vegetable and almost always cooked, such as in a pureed soup or mixed with brussels sprouts, sweet and rich chestnuts are also popular simply roasted whole and eaten while still hot.

You must cook chestnuts by briefly boiling or roasting them to loosen their tough outer shells and thin, bitter skins. If you let the chestnuts cool after roasting or blanching them, they will again become difficult to peel. If they do cool, simply return them to a hot oven or hot water for 5 minutes to warm them up. For large amounts, roast or blanch and peel the nuts in batches, working steadily and without distractions.

Coconut
Like the almond, the coconut is the actual seed of a tree, a palm that grows in almost every tropical area. A dark brown, fibrous husk and a very hard shell enclose the rich, white flesh inside.

Hazelnut
Also known as filberts, grape-sized hazelnuts have hard shells that come to a point like an acorn, cream-colored flesh and a sweet, rich, buttery flavor. They are difficult to crack and usually are sold already shelled.

Macadamia Nut
Usually sold shelled, this rich nut originated in Australia but is now also grown widely in Hawaii. Smooth, off-white and round, it resembles a large chickpea. Macadamias add crunch and sweet, buttery flavor to curries, salads, rice, cookies, candies and ice cream.

Peanut
Actually not a nut but rather a type of legume that grows on underground stems, peanuts are seeds nestled inside waffle-veined pods that become thin and brittle once dried. The peanut has long been a nutritious staple throughout South America, Africa and Asia, where it often flavors curries and garnishes salads. The peanut is also well known in North America in its pureed state as peanut butter.

Pecan
A native of North America, the pecan has two deeply crinkled lobes of nutmeat, much like its relative, the walnut. Hundreds of varieties exist, but they all have smooth, brown, oval shells that break easily. Their flavor is sweeter and more delicate than closely related walnuts.

Pine Nut
The seed of pine trees, nestled in the scales of their cones, pine nuts are small, rich nuts with an elongated, slightly tapered shape and a resinous, sweet flavor. Important in southern Europe and the Middle East, they appear in salads, stuffings and sauces (most famously, pesto), as well as in baked goods and desserts.

Pistachio
Used widely in Mediterranean, Middle Eastern and Indian cuisines, the pistachio has a thin but hard shell that is creamy tan and rounded. Bright red nuts owe their color to vegetable dye. Pistachios are often used in desserts. As the nut ripens, its shell cracks to reveal a light green kernel inside.

Walnut
The furrowed, double-lobed nutmeat of the walnut has a rich, assertive flavor. The most common variety is the English walnut, also known as Persian walnut, which has a light brown shell that cracks easily. Black walnuts, native to North America, have dark shells that are extremely difficult to break. Almost always sold whole, black walnuts are a challenge to find and have a stronger, slightly astringent flavor desirable for desserts. The mild white walnut, or butternut, has a light tan shell

Adapted from Williams-Sonoma Kitchen Companion: The A to Z Guide to Everyday Cooking, Equipment and Ingredients (Time-Life Books, 2000)