Peter Rabbit’s mother was onto something when she put him to bed with a cup of wild chamomile tea after his escapade in Mr. McGregor’s garden. People in the modern world often think of chamomile as a sleep or digestive aid. But wild chamomile is another name for the herb Feverfew. A tea of feverfew would not only have relaxed the hapless rabbit but would also have routed his headache, calmed his upset tummy, put his mind at ease, and...