Lets talk about Pigeon Peas (Cajanus cajan)
They are small trees or shrubs. We have one growing in the garden. Pigeon peas are nitrogen fixers, deep rooted , very edible and easy to grow short lived plants.
The pigeon pea is a perennial legume from the family Fabaceae. Since its domestication in India at least 3,500 years ago, its seeds have become a common food grain in Asia, Africa, and Latin America. Wikipedia
It is very high in protein, potassium, dietary fibre and contains calcium, iron, Vit B6 and magnesium.
You can find out all about this versatile plant at this website.
Growing Pigeon Peas, An Incredibly Versatile Permaculture Plant