It would help to see the whole plant, but I'll guess Austrocylindropuntia subulata.

Here is a better shot...have not seen Austrocylindropuntia subulata with limbs like this.

Yes, A. subulata, and they branch profusely. Give it more to drink and you'll see the fleshy protuberances that characterize the species. They grow fast, yours should look like this 2-3 years after seeing ground.

Whoa...I'd be cutting it back prior to that size. Is this the one known commonly as "Eve's Needle?" Thanks for the info.
Pic is of a similar plant and hopefully I can keep ours close to
this size

Opuntias in general tend to be the fastest in terms of visible growth, and in particular this one is at the head of the class - you might want to install a hook on that pot to hang the machete from. It will take over that pot, but if you give it less-than-usual water and don't feed it that regimen will hold it back a bit. It's a great landscape plant, and in your pot/setting it looks nice, but it's a potted monster. Wash its branches first with hose water before you trim it (that slows down glochid action a little bit) will provide a less-painful pruning program.

This post was edited by cactusmcharris on Mon, Feb 18, 13 at 19:35