Spotting

Another way to distinguish among the three (thanksgiving, Easter, and christmas) is by the edges of their leaf segments. Both thanksgiving and Easter tend to have smooth rounded leaf segments, but Easter has bristled along the edge as well. Christmas has more jagged or pointed edges. And of course the Easter cactus had a star shaped flower whereas thanksgiving and Christmas has two tiers. Anyway they're all beautiful!

http://www.hortmag.com/weekly-tips/qa/ea...
http://www.hortmag.com/weekly-tips/qa/ch...

Found it....http://www.ebay.com/gds/How-to-Care-for-a-Christmas-Cactus-and-Get-Gorgeous-Blooms-/10000000206279098/g.html?roken2=ti.pU3RlcGhhbmllIFJvc2U=

This is cool, what a coincidence! I just read an article a couple days ago about the Christmas cactus and how there are two other variations that look very similar but are in fact different...one is more properly called the Thanksgiving and the other as mentioned here by concy88, the Easter cactus. The main way to tell them apart is by what time of year they bloom, which as I'm sure you guessed, they each bloom in the season of the holiday after which they were named. The article came to me in an email...if I still have it then I will post the link.

Easter Cactus - Rhisalidopsis
http://www.mattslandscape.com/rhipsalido...