Through time, we can know that the agricultural crops of Indians at that time were corn, sweet potatoes, peppers and so on. The domestication of potato was completed by Indian ancestors in South America 8000 years ago. This is one of the most important contributions of Indians to world civilization. Indians also domesticated other foods, such as corn, sweet potatoes, cassava, peanuts and tomatoes. For South American residents, the Andes are cold and barren, and potatoes are more important than corn.

Before potatoes were introduced to America, Indians lived mainly by collecting berries. These berries include blueberries, blackberries and cranberries. They are not only sweet and sour, but also nutritious.

Classification of berries

Berry is a kind of fruit with single meat quality. It consists of one or several carpels and contains one or more seeds. Such as bananas, tomatoes and cranberries. A kind of meat and fruit. There is no obvious difference between the three layers of pericarp. The cells outside the peel are parenchyma cells, and the rest are juicy and seed-bearing, such as grapes, tomatoes and persimmons.

Pumpkin is another kind of berry, which is developed from ovary and receptacle and belongs to false fruit type. This kind of berry is called Zan Guo. Citrus fruit is also a kind of berry, which is characterized by tough skin and oil sac on it; The mesocarp is loose and the vascular system is orange complex. Endocarp is membranous, divided into several chambers, and numerous fleshy juice sacs are produced indoors, which are orange petals that people eat.