The only way I can tell the cashew varieties apart is by the color of the fruit - and the nut is not the fruit. The nut, also called maranon, is almost an accessory to the actual fruit which is called a cashew apple. The cashew apple, whether red or yellow, is delicious for eating right off the tree or for turning into juice. The skin of the cashew apple is so fragile that the fruit doesn't travel well. So, if I had not gone into the cashew-tree world I wouldn't have known there was anything but the nut, but that's all that most of us know about cashews anyway.
As for the purpose-driven, we've planted lots of food: dasheen (taro), cassava, sugar cane, pineapple, banana, rice, beans, corn, various other vegetables and some herbs. So far the herbs are those that are good for tea, like lemon grass (shown below).
Cassava roots grow just below the surface of the soil and radiate around one or more stems that grow straight up. Unpeeled, cassava roots looks something like really long sweet potatoes; peeled, however, the flesh is white and can be cooked in lots of ways. It can be cooked in most ways you'd cook a potato: mashed, fried, or made into a salad. Some cooks can also turn the root into a sweet moist cake.
I'm probably not the only person familiar with the plant who thinks that, along with some protein, it could feed the world. We planted cassava in late November and by May we were harvesting and eating the roots...and what roots they were, some as long as four feet! We got two good meals from this plant.
Cassava is quick to mature, easy to harvest, and easy to replant. Once the edible roots are removed from around the base of the stems, the leaves are stripped from the plant and the stems are then cut into pieces, each eight to ten inches long. Drop each piece of stem into a shallow hole, cover it (most people just shove dirt over the stem piece by foot - saves all that bending over), and wait six or seven months. So, not only do you get a meal or two from each harvested plant, but you've got the potential to get ten to fifteen new plants from each harvested plant.