Cereal grass and Rice grass

Cereal grass noun - Grass whose starchy grains are used as food: wheat; rice; rye; oats; maize; buckwheat; millet.

Rice grass and cereal grass are semantically related. In some cases you can replace phrase "Rice grass" with "Cereal grass", this phrases are similar.

Rice grass noun - Any grass of the genus Oryzopsis.

Cereal grass and rice grass are semantically related. You can use "Cereal grass" instead a noun phrase "Rice grass".