California Poppy is the first plant that comes to mind. Although it contains none of the opiates that this family is famous for, it has a very similar calming effect on the nervous system. It works particularly well for PMS related stress as it has pain relieving and muscle relaxing benefits as well. The whole above ground plant, leaves, flowers and all can be made into a relaxing tea.
St John’s Wort needs no introduction. It is a wonderful plant to treat stress, anxiety and depression. It is used primarily for nervous function for which is has a calming, restorative influence, whether the symptoms are physical or emotional. It will ease the pain of any nerve-related problem as well. The leaves and flowering tops can be made into tea. Please see the full article for contraindications to use.
Chamomile is an oldie but a goodie. It has held an esteemed place in the home herbal medicine arsenal for hundreds if not thousands of years. And for excellent reason, as it is a very reliable relaxant, calming the nervous system without undue sedation. I works well for children, and because of it’s calming effect on digestion, it settles an anxious stomach. Pick a few flowers for your tea and get ready to relax and let go.