My Colleague Ivan just asked me today about the strange green balls which are selling all over the Super Market now 

It is Qingtuan (Chinese: 青团, literally “green cake”) is a traditional Chinese dish. This food, which looks like a round green stone, is made of rice, red bean paste and a special plant called maiqing (麦青) (barnyard grass shoots) or aicao(艾草). The exact technique in making qingtuan is quite complicated. Barnyard grass shoots are edible only in spring,

The best green ball dumplings are made of Aicao, it is a special plant which is wildly used in China as a type of traditional herb medicine. So it is more expensive than maiqing, cost wise and people believe it is better in taste.