Which five grains specifically do the five grains among the five grains and miscellaneous grains refer to?

I. What does it refer to

The five grains refer to wheat, corn, rice, soybeans, and tubers, but at the same time grains other than rice and flour are also habitually called miscellaneous grains, and the five grains and miscellaneous grains are also broadly referred to as food crops, so the five grains are also a general term for food crops.

II. Historical origins

The term five grains and miscellaneous grains has a very long history. Chinese people have followed a diet based mainly on grains for thousands of years. As early as 2,000 years ago, it was mentioned in the book Huangdi Neijing. People generally consider wheat and rice to be fine grains, and miscellaneous grains refer to other grains besides these. What we now call five grains and miscellaneous grains includes a variety of grain and bean foods, such as: corn, millet, barley, black beans, broad beans, mung beans, peas, sweet potatoes, and so on.