Boxwood (box, Buxus, smoke tree) is an evergreen shrub native to Southern Europe, Western Asia, and Northern Africa. It's extract used for rheumatoid arthritis, diarrhea, stomach pain, hernia pain, abdominal distention, pain, bruises, swelling, sores, and carbuncles. Fisetin, a flavonol found in boxwood, was first described by Austrian chemist Josef Herzig in 1891 and it has shown anti-aging, anti-inflammatory, anti-cancer and anti-viral properties in clinical studies. Boxwood extract is also used to treat HIV/AIDS and to boost immunity. Fisetin is a flavonol, a structurally distinct chemical substance that belongs to the flavonoid group of polyphenols.