Originally our grasslands consisted mostly of perennial species such as needle grass, melica, wild rye, native bluegrass, and deergrass, along with a variety of legumes, sunflowers, and annual wildflowers. But since the introduction of agricultural and weedy varieties by early European settlers, the native grasses have all but disappeared. Our natural grasses consisted primarily of perennial bunch grasses possessing tender stems and leaves favored by herbivores such as deer, antelope and rodents. The presence of these animals provided vitality to the land through light grazing and soil cultivation by the burrowing species.

However, with the introduction of large numbers of cattle following the mission period, the native grasses were trampled and eaten into near extinction. Any natural trend toward reestablishment of these species was soon quelled by the pressure of increasing numbers of cattle who preferred the tender native species to the invading annuals. Most of these invaders, such as foxtail fesque, ripgut grass, and red brome, possess sharp spines and barbs and other objectionable characteristics. Therefore, they were passed over by cattle for more favorable varieties, allowing the weedy species to spread uncontrolled throughout the grasslands. The success of these weeds may also be credited to their ability to grow rapidly under unfavorable circumstances, and to produce numerous seeds with effective mechanisms for dispersal. Today, even though they originated in other parts of the world, these tenacious species of grasses, along with a variety of other weeds, dominate our grasslands.

Aside from the grasses, legumes and forbs are also present in the grassland complex. Among the legumes are the clovers, locoweeds, and various species of lupines which are important to the environment as nitrogen fixers. The forbs are represented by many other plant groups, especially those from the sunflower family.
The following species represent examples of native and introduced grasses, and nongrass members typical of the grasslands and the southern oak woodland.*