The chamomile listing of Wikipedia has a whole section devoted to what is in the plant that gets infused into tea. Not fair for me to repeat when it is at your fingertips.
@pleiades I understand. However the effects of chamomile are generally agreed and accepted.
However there was a peer reviewed study done in 2004–2005 on the effects of chamomile and one of the places the results were published was sciencedaily.com
Actually it focused on its antibacterial properties but i believe there was a brief explanation as to why chamomile was an antispasmadic and relaxant.