Legumes are plants in the pea family which produce pods which dehisce, meaning that they split open naturally along a seam, revealing a neat row of seeds. Legumes are cultivated for both human and animal food, in addition to being grown as ornamentals, and they can be found growing on every continent, demonstrating the adaptability of the over 18,000 species considered to be legumes. Chances are high that you've eaten a legume in the last week, and you may have seen one growing, as well.

The defining feature of legumes is the pods, which can vary in size and length, depending on the plant. When allowed to grow naturally, the pods will split open as they dry out, releasing the seeds and allowing the plant to spread. Some legumes even pop open almost explosively, projecting the seeds to cover the area more widely.

Humans have been growing and eating legumes for a very long, with archaeological evidence suggesting that legumes may be the oldest crop known to man. Many legumes were probably naturally edible before domestication, while others developed more plentiful, large seeds as a result of domestication. Some well known legumes include beans, peas, peanuts, lentils, lupin, alfalfa, clover, and vetch, among many others. In addition to having edible seeds, some legumes also have useful foliage which can be used to feed animals; other legumes are planted as forage crops for creatures like cattle.

When dried, legumes are known as pulses. Pulses are famous for being able to endure extended periods of storage, making them a very useful food to grow, because they can be eaten during lean periods. Legumes are also very high in protein, making them an excellent addition to the human diet, and many have a rich assortment of vitamins and minerals as well. Because of their nutritional value, legumes play a very important role in the diets of the world's poor, and they are quite popular with wealthier individuals as well.

Legumes are also good for the soil. They are adept nitrogen fixers, meaning that they pull atmospheric nitrogen into the soil; this trait can help to restore soil which has been depleted of nitrogen by other crops. Legumes are therefore included in crop rotation, and sometimes coplanted with various vegetables to ensure that the soil will not be stripped of its useful nitrogen by greedy plants.