They're sometimes called "ponytail palm", but, it's not a real palm. They're very easy to propagate, too. Once they've grown taller, cut them back (any height) and they'll sprout 2 or 3 new canes from the stump. Stick the cuttings in soil, and they'll take root. Also, once they're taller, bend the cane by tying it down with a strong string. The top will turn toward the light, creating a pretty curving shape. At least, this is what happens with them when they're grown outdoors in S. Fla. I'm not sure how they do indoors in cold country.