Grasses are one of the most common plants found on the westward expansion. They grow in a variety of climates, from dry, desert regions to lush, green valleys. Some of the most common grasses include:
* Buffalo grass
* Blue grama grass
* Western wheatgrass
* Needle grass
* Prairie cordgrass
Trees
Trees are also found in a variety of habitats on the westward expansion. In the eastern United States, forests are dominated by deciduous trees, such as oak, hickory, and maple. In the western United States, forests are more likely to be coniferous, such as pine, spruce, and fir. Some of the most common trees found on the westward expansion include:
* Oak
* Hickory
* Maple
* Pine
* Spruce
* Fir
* Douglas fir
* Ponderosa pine
* Western red cedar
Shrubs
Shrubs are found in a variety of habitats on the westward expansion, from deserts to mountains. Some of the most common shrubs include:
* Sagebrush
* Rabbitbrush
* Bitterbrush
* Greasewood
* Creosote bush
* Chamise
* Manzanita
* Ceanothus
* Mountain mahogany
Cacti
Cacti are found in the deserts of the western United States. These plants have adapted to the dry climate by storing water in their tissues. Some of the most common cacti include:
* Saguaro cactus
* Prickly pear cactus
* Cholla cactus
* Barrel cactus
* Ocotillo