It is from the Apocyanceae Family and has many apt common names including Chain of Hearts, String of Hearts, Collar of Hearts and Rosary Vine etc. 2 links are attached below:
- http://en.wikipedia.org/wiki/Ceropegia_woodii
- http://mrbrownthumb.blogspot.com/2007/08/ceropegia-woodii-string-of-hearts.html