Drainage basin: The area drained by a river and its tributaries. A drainage basin is considered to be an open system because water can be added or lost from a drainage basin. Source: The beginning of a river. A river may have multiple sources.
Milk thistle (Silybum marianum) is a thorny plant presenting decorative leaves with a white pattern of veins and purple flower heads. The plant originates from mountains of the Mediterranean region, where it forms scrub on a rocky base.
1 Milk thistle contains the flavonoid silymarin, which is responsible for many of its beneficial effects, including liver protection and antioxidant, anti-viral, and anti-inflammatory properties.  Milk thistle may fight liver disease and reduce liver injury caused by a number of drugs and environmental toxins.