Other contributors have said "What are the verities of plants called in a grassland?" is the same question as "What grassland plants are edible?" If you believe that these are not asking the same thing and should be answered differently, click here
To the herbivores that live on these grasslands, yes, most are. However, there are plants that are poisonous to animals that are not edible. Locoweed, Death Camas, Water Hemlock and Tall Larkspur are...