Although there are more than 3 elements, the core trio is corn, beans and squash. In American Indigenous agriculture these 3 crops provided the basis of the cultivated diet (wild foods of course played a significant role.) There are stories, history and culture enmeshed in this planting system which I am not qualified to speak of, although they play a significant role in American indigenous cosmology and worldview.
The squash provides much needed storable vitamins as well. Other elements such as sunflowers provide food (an important source of oil), nectar for pollinators and habitat for beneficial insects. We also use them as a trellis.
This corn is an heirloom open pollintated variety of multi colored glassy kernels used for grinding and popping. We pay our respects to all the indigenous gardeners and plant breeders who have related to these plants for 1000s of years. I am deeply grateful for all those plant people who came before and worked tirelessly to create the rich diversity of plants we enjoy today.
Beans on the left and purslane on the right.