Milk thistle, Silybum marianum L. syn. Carduus marianus, growing in my yard.  Leaves are edible, (strip away spines).  Seed is used to treat liver disorders, mushroom poisoning, chemical destruction of liver, etc.  (More)

 Yet to be proven use:  preparations used as a central nervous system stimulant.
Milk thistle seeds contain silymarin, used to treat liver problems, reported to regenerate liver cells and protect them from further damage.