Toxicological trivia from September 17, 2014: Silybum marianum has other common names include cardus marianus, milk thistle, blessed milk thistle, Marian Thistle, Mary Thistle, Saint Mary’s Thistle, Mediterranean milk thistle, variegated thistle and Scotch thistle. This species is an annual or biennial plant of the Asteraceae family. This fairly typical thistle has red to purple flowers and shiny pale green leaves with white veins. Originally a native of Southern Europe through to Asia, it is now found throughout the world. The seeds of the milk thistle have been used for centuries for medicinal purposes. Of these substances as silymarin or silibinin are obtained. Other substances present in medicinal interest thistle seed are: a) Silidianin; b) Silychristin; c) Both previous statements are correct. 

Correct answer: c.  Read more in WP.