Here's a link to an interesting and informative guide to Famine Food in Ethiopia.

For many years the importance of wild plants in subsistence agriculture in the developing world as a food supplement and as a means of survival during times of drought and famine has been overlooked. Generally, the consumption of such so-called ‘wild-food’ has been and still is being under-estimated. This may very well be the case for Ethiopia, a so-called ‘biodiversity hot-spot’ and known as a centre of origin for a significant number of food plants (Bell, 1995).”

Ethiopia: Famine Food Field Guide