Cindy Murphy, age 13, of Pocatello, Ida., for her question:

WHAT EXACTLY IS A LEGUME?

A legume is any of the plants that belong to the pea family. They actually make up the second largest family of flowering plants. There are about 13.000 different kinds of legumes.

The group gets its name from the legumes, or seed pods, that most of the plants in the family bear.

Peas, beans and peanuts are legumes that are valuable foods. Alfalfa, clover and vetch are legumes that are important forage and pasture plants.

Legumes grow in most parts of the world. They vary widely and  may be trees, shrubs or herbs. Many are climbing plants. The flowers of some legumes may be small and regular while others may be irregular with spreading petals.

The flowers of one large group look like butterflies. Botanists call this group Papilionoideae, from the Latin word for butterfly. The common sweet pea belongs to this group. Legumes take nitrogen into their roots from the air and change it into forms that can be used by the plants. This characteristic makes leguminous plants valuable in agriculture. Farmers often use them as green manure and as cover crops to improve poor soil