Oil crops are plants that are grown primarily for the oil that they produce. Major ones include such well-known plants as soybeans and canola as well as a number of other plants with other uses, such as avocados, grapes, and almonds. In addition to the designated crops, non-petroleum oil also comes from animals and from corn and cotton, all of which have uses other than the production of oils. While the best known application of oil crops is in the production of edible oils, they can also produce inedible oils and even biofuels.
The major oil crops are typically used to produce edible oils. They include soybeans, peanuts, sunflowers, and canola, which is a genetically engineered form of rapeseed, originally developed in Canada. Linseed oil, also known as flaxseed oil, was originally produced for industrial applications, such as the manufacture of paint, but has gained prominence in the United States as a nutritional supplement is eaten in countries in Europe.
In addition to the well-known crops, a number of other plants are grown for use in oil production. Edible oil plants include a number of nuts, gourds, and fruits. Inedible oils can also come from almonds, papayas, and even tung beans, which create an oil used to seal wood. Essential oils come from crops that include wormwood, patchouli, and chamomile.
Some crops have uses other than oil production. While cottonseed oil is a useful product, most people think of cotton as being grown for its fibers. Corn has myriad uses other than providing its oil. On the other hand, while soybeans provide useful protein for humans and animals, most of it is used for oil, making it primarily an oil crop.
In the early 21st century, oil crops are beginning to serve a completely new market: cars and trucks. Many vegetable oils can easily be turned into biodiesel fuel that can power most diesel engines with, at most, relatively minor modifications. In addition to traditional crops like safflower, soybean, and canola, biodiesel can also be made from waste cooking oils or from alternative crops, such as Carmelina saliva, also known as "false flax" or "gold-of-pleasure."