Cereal grass and Pennisetum glaucum

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

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

Pennisetum glaucum noun - Tall grass having cattail like spikes; grown in Africa and Asia for its grain and in the United States chiefly for forage; sometimes used in making beer.

Cereal grass and Pennisetum glaucum are semantically related. You can use "Cereal grass" instead a noun phrase "Pennisetum glaucum".