You've got some nice ones there. The third and fourth pics in your second post are both some really healthy opuntias. The one with the white spices is particularly beautiful... not to mention it's particularly impressive to see it in flower.
With apologies to the late Professor C. D. Darlington the following misquotation springs to
mind ‘cactus taxonomy is the pursuit of the impossible by the incompetent’ - Fearn & Pearcy, Rebutia (1981)
