Manioc AKA Cassava

Even though I don't go looking for roots, in the course of 48 years of field geology I've dug a lot of holes. Many plants have roots with bulbous parts. I'm sure indigenous peoples would know which can be eaten and which can make you sick. Being perennials, their roots would be in the ground even after their leaves have fallen or been eaten by ruminants. If starving, it would be second nature to dig around to look for anything edible. And if on the move it makes sense to carry portable foods just in case you cannot find food, like we do on backpacking trips.