Of course there is a lot more information available on these herbs and their uses, but below I have added a few snippets regarding what I know of them. As with any herb, do extensive research and perhaps even consult a professional before self medicating.
Pennyroyal: (as stated in an earlier post) Probably the most dangerous emmenagogue and reported to have been used by Native American Indians for centuries to induce abortion. This would also classify it as an abortificient. Also, Kurt Cobain apparently drank it daily to help with stomach ailments.
Tansy: Also an emmenagogue used to promote menstruation and cause herbal abortions. Read more about these uses here: http://www.sisterzeus.com/Tansy.htm.
Borage: Self seeding annual. Reported in older times to give courage to any who consume it. Also reported to counteract depression and cause a mild euphoria.
Horehound: Long known for its help with lung ailments and coughs.