The vegetation communities of Yellowstone National Park include overlapping combinations of species typical of the Rocky Mountains as well as of the Great Plains to the east and the Intermountain region to the west. The exact vegetation community present in any area of the park reflects the consequences of the underlying geology, ongoing climate change, substrates and soils, and disturbances created by fire, floods, landslides, blowdowns, insect infestations, and the arrival of nonnative plants.
Today, the native taxa in the park represent the species able to either persist in the area or recolonize after glaciers, lava flows, and other major disturbances. Yellowstone is home to three endemic plant species, at least two of which depend on the unusual habitat created by the park’s thermal features. Most vegetation management in the park is focused on minimizing human-caused impacts on their native plant communities to the extent feasible.
There are several vegetation communities in Yellowstone: higher- and lower-elevation forests and the understory vegetation associated with them, sagebrush-steppe, wetlands, and hydrothermal.
Wildflowers can grow under the forest canopy, but the most conspicuous displays occur in open meadows and sagebrush-steppe.
The Greater Yellowstone region has few endemic plant species, or species that occur only in Yellowstone and nowhere else in the world. Endemic species occur in unusual or specialized habitats such as hydrothermal areas. Within Yellowstone, only three endemic species occur: Ross’s bentgrass (Agrostis rossiae), Yellowstone sand verbena (Abronia ammophila), and Yellowstone sulfur wild buckwheat (Eriogonum umbellatum var. cladophorum).
Several other unusual species live in the Greater Yellowstone Area: warm springs spike rush, which grows in warm water; and Tweedy’s rush, sometimes the only vascular plant growing in acidic hydrothermal areas.