The light streaks are red rice (Oryza sativa) growing along ditches in a rice field. It gets its name from the red pigment in the bran layers. It is by far the most serious weed of rice. Red rice is a weedy form of cultivated rice. It belongs to the same genus and species of cultivated rice. It exists in many forms, most of which are taller than cultivated varieties. Red rice is also lighter in color than cultivated rice in most cases. This aids in locating it in cultivated seed rice fields where it must be removed by hand in conventional varieties.

Red rice may have awns (long extensions of the lemmas of rice) or be awnless. Some forms of red rice have dark hulls and are comonly called black hulled red rice. In this photograph are three types of panicles of red rice. All are pubescent (have tiny hairs) but one is black hulled, one is straw hulled, some have awns. There are many forms of red rice.