Monocotyledons - one of two large groups of flowering plants. According to the name, these plants have an embryo with a single cotyledon. The best-known plants in this group are the cereals, such as wheat, rice, and maize. The main weeds that belong to this category found in most regions are black grass, johnson grass, annual meadow grass, cockspur grass, common windgrass, large crabgrass, green foxtail, yellow foxtail, rye brome, common wild oat, couch grass, and bermudagrass.