I was happy to discover that the National Library of Medicine has a medicinal herb garden, started in 1976 as part of the Bicentennial celebrations. It is maintained by volunteers from the Montgomery County Master Gardener Association and the Herb Society of America, Potomac Unit. The garden contains around 100 species of herbs, all historically valued for their curative powers.
The picture below is from NLM’s garden. The pink flowers in the foreground are yarrow, historically used for minor abrasions and allergies, and the lavender ones behind are (shockingly) lavender, used to ease stress and nausea.
For more details, visit https://www.nlm.nih.gov/about/herbgarden/index.html