Here in Peru is called "Sacha papa" or wild potato (papa silvestre) and there millennia, and is the delight of the jungle, also use it to prepare liquor "masato" there are varieties, but the main ones are the white and purple
In Lima are all safe are in the vegetable markets
As for the Okra, here in Peru we call "algalia", "yerba de culebra", "ají turco", quimbombó"(there's even a salsa song called so: https://www.youtube.com/watch?v=-vVODtyTMwg
), "Bolondrón", or "ñaju" and taken as emollient. You should also search the large markets of Lima or ask those who sell emollients in lima, where they buy it.
pumpkin seeds (semillas de calabaza) the give away, no commercial value so that you can get free vegetable market. Go to any market and the will or any plant nursery ("vivero").
black beans (frijol negro) know enough, there's even a recipe for black beans to the Peruvian. Also go to a market to get them.
As Cassava (Yuca) is quintessential food in Peru, take care to get them fresh,here are prepared in a variety of dishes and also as garnish(cebiche) and we put a pinch of salt for flavor, but in the jungle eat them insipid and also make them liquor.