You're right about the Mamms, but that "I'm a sucker for hoked spines" comment, I don't know about that one. I actually made an order last week for a different species of Mamm, but I ended up with the M. bocasana, and that thing is unforgiving when it sticks you
It has hooked me twice, the first time unwrapping it, and once when I was reaching for another cactus next too it. The second time I got hooked, by two of the spines. It hooked me so good I actually pulled the plant right out of its pot
I respect them hooked spines now, trust me! I take extra care now when I work near that plant.

"There is something fascinating about science.One gets such wholesale returns of conjecture out of such a trifling investment of fact."- Mark Twain(1835-1910)