Milk Thistle (Silybum marianum)
With appologies to Eric Idle and all the other sophisticates who enjoy a good fart joke, the genus of this ubiquitous little plant really is Silybum.
Milk Thistle has a long history as an herbal remedy, usually for liver damage caused by chemicals, alcohol, chemotherapy, Amanita phalloides (death cap) mushroom poisoning, jaundice, chronic inflammatory liver disease, cirrhosis of the liver, or chronic hepatitis. Persons with allergies to the Asteraceae plant family (including ragweed) may find they are also allergic to milk thistle. See the Wikipedia article for more information: https://en.wikipedia.org/wiki/Silybum_marianum