Re rice, also known as weedy rice, is a species of rice that produces far fewer grains per plant than cultivated rice and is therefore considered a pest. Because red rice and cultivated rice are so closely related, herbicides that would kill red rice would also kill cultivated rice. A genetically modified form of cultivated rice has been developed that will resist a herbicide, but this form of rice has not been approved for human consumption. This genetically modified form of cultivated rice has, however, appeared on the rice market.