Damiana  Leaf:  (Turnera Diffusa) This small fruit that is native to Central/South America, Mexico  and the Caribbean is used for many medical issues but the original finding was for an aphrodisiac. Acutually many parts of the plant are used.
The following is short list of it's uses:
Made into a tea, it is used for,
Fibromyalgia
Boost Energy
Emphysema
Low estrogen Output
Menopause
Hot Flashes
Impotency
PMS
Prostate Issues
Male/Female Reproductive Issues

It's recreatioinal uses are  found  in the Mexican drink, Margarita.  It is smoked as it is used in herbal cigarettes. It's main substance, damianin, has a relaxing effect on the nervous system.

Adverse Side Effects: Used in moderation, no negative results have been reported to date.