Chamomile is a main ingredient in those sleepy time and nighttime teas you bought and never used. They're sitting in your cupboard right now. The chamomile flower is used in teas and baths. The flowers have a circular yellow center and little tiny white petals. As with the catnip, you can find the live plant at any nursery or get the dried flowers at a natural food store.
Chamomile is easy.
Two or three heaping teaspoonfuls of chamomile flowers per cup of boiling water makes a wonderful, relaxing, digestive tea. I suggest no more than three cups a day. To avoid floating weeds in your cup, use the straining idea I suggested above. For teas, I generally use store bought. Less mess and no fuss.