What are some characteristics of the rapeseed plant?

The rapeseed plant, a large annual in the Brassicaceae family, is characterized by yellow, four-petaled flowers, a deep taproot and a fibrous, near-surface root system. It grows to heights of 3 to 5 feet, and its seeds, which contain more than 40 percent oil, are often used for industrial purposes.

The plant comes in two varieties -- industrial rapeseed and canola -- distinguished by the percentage of erucic acid present in the oil of its seeds. Generally, industrial varieties are used in non-edible applications, such as bio diesel, machine lubricants and the manufacture of plastic film, while canola is the third-largest source of vegetable cooking oil in the world.