Rapeseed

Rapeseed, also known as oilseed rape or canola, is a yellow-flowered plant that belongs to the Brassicaceae family. People grow it mainly for its seeds, which are full of oil. These seeds have something called erucic acid, which can be harmful, but special kinds of rapeseed called canola have very little of this acid. This makes them safe and useful for food.

Rapeseed is very important around the world. It is the third-largest source of vegetable oil. People use this oil for cooking and other things. The seeds also give a lot of protein, making them helpful for animals that people raise for food.

Even though rapeseed can be used in many ways, not all types are safe for eating. The special canola types were made to be safer for both humans and animals. This plant grows in many parts of the world and helps provide food and other products for many people.

Description

Rapeseed, also known as Brassica napus, grows up to about 100 centimetres (39 inches) tall. Its lower leaves are hairy and have stalks, while the upper leaves do not. The flowers are bright yellow, about 17 millimetres (just under an inch) across, and have four petals arranged in a cross shape.

The pods of rapeseed start green and elongated, later turning brown. They grow on small stems and each pod contains a row of small, round, black seeds. Rapeseed can be told apart from similar plants by its smaller flower petals, which are less than 13 millimetres (about half an inch) across.

Taxonomy

The species Brassica napus belongs to the flowering plant family Brassicaceae. Rapeseed is a subspecies called B. napus subsp. napus. It has types such as winter and spring oilseed rape, and vegetable and fodder rape. A related plant is Siberian kale, a leaf variety once commonly eaten as a winter vegetable.

Brassica napus formed naturally from the mixing of two different plants: B. oleracea and B. rapa. Like other similar plants, it can pollinate itself. The word "rape" comes from the Latin word for turnip, showing its old link to root vegetables.

Ecology

Rapeseed, also called oilseed rape and canola, can sometimes grow where it isn't planted. You might see it along roadsides or in empty spaces. This happens in places like Northern Ireland, where the plant has been seen growing naturally in such areas.

Cultivation

Crops from the genus Brassica, including rapeseed, have been grown by people for about 10,000 years. Rapeseed was first grown in India around 4000 B.C.E. and later spread to China and Japan.

Rapeseed is mostly grown in its winter form in Europe and Asia. It is planted in autumn, stays on the ground as leaves during winter, and grows a tall stem in spring. It usually flowers in late spring and makes seeds over the next six to eight weeks. In Europe, winter rapeseed is often grown in rotation with crops like wheat and barley to help stop pests and diseases. Spring rapeseed, grown in places like Canada and Australia, does not need the cold winter to start flowering and is planted in the spring instead. Rapeseed grows well in many kinds of soil and likes a balanced pH level between 5.5 and 8.3. It is usually pollinated by wind but can make more seeds when bees help with pollination.

Uses

Rapeseed is grown to make vegetable oils, animal feed, and biodiesel. It was the third most common source of vegetable oil in the world in 2000, after soybean and palm oil. It is also the second most common source of protein meal, used as animal feed, after soybean.

Rapeseed oil is one of the oldest vegetable oils known. Modern varieties, called canola, have very low levels of a natural plant substance that can be harmful. This oil is safe for people to eat and is used in many foods. When rapeseed is processed to make oil, the leftover material, called rapeseed meal, can be used as feed for cattle, pigs, and poultry. Rapeseed oil can also be used as fuel for cars, called biodiesel, and is especially popular in Europe. Rapeseed is also used to help protect soil and provide food for honeybees.