Hi Wendy - its a homeopathic remedy which also goes by the name of Blue Cohosh. Amongst its many uses, it is said to alleviate the pains associated with giving birth/delivering babies/parturition. Some people say to give it during the delivery if you notice your queen flagging a bit and some say to give it as soon as the onset of delivery is noticed or at first stage of labour.
Here is a link which tells you a bit about
Caulophyllum
There are plenty of other places where information about it can be found.