View photos of the medicinal plant Hyoscyamus niger (Henbane), profiled in Medicinal Plants of the Western Mountain States.

A passage from Medicinal Plants of the Western Mountain States:

Henbane’s safest and most reliable utilization is its topical application to most things painful and swollen. The ointment or liniment are fine preparations for pain relief from contusions, bruises, and blows. It’s an effective choice as a post–workout martial–arts liniment. For arthritic joints, chronic neuralgias, and headache pain try a warm fomentation made with the strongly brewed tea. A liniment–soaked cloth can be applied as well to the same problems if the warmth of the fomentation is contraindicated. Upon availability of the fresh plant, the juice from the crushed leaf (or a fresh leaf poultice) too can be topically applied for similar issues.