Darla Fogarty, age 13, of Gadsden, Ala., for her question:

HOW TALL DOES A PISTACHIO NUT TREE GROW?

A pistachio nut tree grows well in dry regions in the Southern United States, in California and in the eastern Mediterranean region. The tree isn't big it seldom rises over 30 feet high. Its branches, however, spread widely.

The small seed of the pistachio tree is called a pistachio nut and sometimes a green almond. The nut may be 1 inch long with a smooth, thin, hard shell that tends to open at the edge much like the shell of an oyster. Its thin, smooth husk or skin is pale red to yellow. The husk is removed before the kernel is processed.

The kernel may either be eaten as a nut or ground and used as a food flavoring and coloring. In the Mediterranean region, the kernels are sometimes processed for their oil.

Every pistachio tree is either male or female. In order to produce nuts, the female tree must have a male tree nearby to produce pollen for its flowers.