Cactus, succulent or something else?

[GreenPicco]

Hello, I got this plant at the Home Depot a couple of weeks ago and despite my best efforts, I haven't been able to correctly identify it. It was among many cacti, in a section for easy-to-care plants. It just had a sticker underneath that said it was a cactus. There was a large sign that had a few hints such as to water it once or twice a month and to keep it in a well-lit area, but little else besides that.

The pot in which it came doesn't have any holes to drain excess water, which makes me believe I should water it in very small quantities as to not oversaturate the soil. Also of note is the fact that the pebbles on top of the soil are hard, as if glued-on (meaning that if I were to turn the pot upside down, the pebbles would not move at all).

The plant has a triangular column with a strange growth on top. I assume that there were spikes along the ridges of the column, because just one small spike remains almost at the top of the column. The rest seem to have been removed for some reason. The growth on top of the column has a pink-ish color and very small, pink petals/leaves along it's ridge.

I haven't watered it yet, since I've only had it for a couple of weeks. I keep it on my desk at work, where it gets a good amount of sunlight until about 8:30 to 9:00 AM. The rest of the day, the only light it gets is the overhead fluorescent light.

Can anyone help me identify my plant and maybe give me some tips on how to better take care of it? Here are two pictures I just took of it:

http://www.prtc.net/~picard/pics/CactusSucculent01.jpg
http://www.prtc.net/~picard/pics/CactusSucculent02.jpg

Any help would be appreciated,
- GreenPicco

[daiv]

You've actually got a Euphorbia on your hands there. See the topic titled "What type of cacti is this . . ." for more info.

[LadyStar]

This is Euphorbia lactea cristata.