I would suggest O. Humifusa.

I'm curious- suppose I wanted to clip back the spines so the plant would ship better- would the spines grow back or not?

Thanks for all the answers. I'm glad I didn't dive into a massive repotting effort with that stuff. I usually use equal parts sand and regular potting soil and plenty of perlite- especially for the larger ones, since they can weigh a ton.

Has anyone used the Miracle-Gro Cactus, Palm and Citrus Soil? It looks new. It looks too rich for cacti and it seems to hold the moisture too long.

I've been growing Euphorbia Myrsinites (Donkey Spurge) for a while now. From a distance it looks like a Burro's Tail but upon closer examination the leaves are heart shaped. It's an Old World plant, and it looks attractive to me, but out West it's considered a weed. It's supposed to be invasive but ...