Midlatitude Grassland Vegetation
Vegetation. Perennial grasses and perennial forbs [especially Compositae (or Asteraceae, depending on the taxonomic system used) and Leguminosae--the sunflower and pea families, respectively] are dominant growthforms. Two or more strata of grasses (erect grasses and recumbent species) are recognized in the more humid expressions of the biome.
Grasses. Perennial grasses, with their growth buds at or just below the surface, are well-adapted to drought, fire, and cold. The tiller or narrow, upright stem reduces heat-gain in the hot summers; the intricate root systems trap moisture and nutrients. Two basic types are: