which of these are edible?

Over here there are yams being sold by the name of ñame. White and yellow ñame, as well as Boniato and Malanga. Boniato is like spanish sweet potato that is white in color (the flesh) and less sweet. I LOVED this when I was vegan Fried.

I don't know where you are, but in the US most yams are mislabeled sweet potatoes. I don't eat these raw, but some on here do. Boniato is just a type of sweet potato. Malanga is a relative of taro, and is treated like sweet potato(boiled or fried). The word "ñame" refers to true yams(which the Boniato and Malanga are not), descended from the yams of Africa. The raw leaves of most tubers are slightly to very toxic, but generally edible cooked. Most sweet potatoes and most true yams can be eaten raw, but in the latter case, cultures that do eat them raw tend to soak them in acid and salt solutions to remove bitter slightly toxic oxalates and other protective chemicals of the plant. If you're really curious, try doing this with a small amount of raw Boniato and see what happens. I wouldn't try this with Malanga because of its relation to Taro, which is toxic raw. Good luck.