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.
Sow thistles are known as milk thistles in some regions, although true milk thistles belong to the genus Silybum. Sow thistles have been used as fodder, particularly for rabbits, hence the other common names of hare thistle or hare lettuce.They are also edible to humans as a leaf vegetable; old leaves and stalks can be bitter but young leaves have a flavour similar to lettuce.onchus species are used as food plants by the larvae of some Lepidoptera including Celypha rufana and the broad-barred white, grey chi, nutmeg, and shark moths. The fly Tephritis formosa is known to attack the capitula of this plant.