I would suggest the following.
Consider teaching about Bush beans and Pole beans.
Pigeon peas,Garbanzo beans are common in Asia and Africa.
Runner beans or scarlet beans are common in Europe.
You may grow Mung amd Muth or Math beans and cow peas.
At the same time you may consider to explain the students the term Legumes.
All seeds are available in Veg. seeds co.s, Ethnic food markets and grocery stores.
Good luck.

The broad bean(Vicia faba). the cowpea(Vigna unguiculata) , the hyacinth bean ( Lablab purpurous), the Bambara bean (Vigna subterranea) and the Yam bean (Pachyrhizus erosus) are natives of Africa. The Bambera grows like a peanut, The Yam bean is called a Jicama in the US
Middle east, garbanzo beas/chickpeas (Cicer arietinum), lentils (Lens culinaris)

Pics. of Bean plants.
Moong Bean.(Large plant) Math Bean(Small plants)

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Scarlet or Runner Bean plant

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