1. I am guessing some kind of Euphorbia, but not sure.
2. Dickia/Hechtia.
3. Euphorbia.
4.A cactus maybe a monstrose form reverting to some extent, the monstrose makes me think of E. lageniformis (I may have the species name wrong, and if not probably the spelling, sorry).
5. A manfreda, I think.
