Walnut
There are several kinds of walnut, the Persian walnut (by far the most common), the Black walnut (more flavorful and expensive), the Butternut, the Japanese walnut and others. Walnuts are very similar to pecans.
Walnuts go well with chocolate, making an excellent ice cream topping.
Recipes featuring walnuts include
Snezhanka
Madeira Honey Cake
Butter tart
Pesto (as a pine nut replacement)
Brownies
Saucepan Fudge Crackle Cookies
Molasses Cookies