About the Flora of Oklahoma

The term flora refers to all the plant life living in a particular region.  Oklahoma has a diverse flora and vegetation, reflecting its geographic position astride 10 North American ecoregions. The vascular flora of Oklahoma comprises ~175 families, ~870 genera, and ~2540 species. It is a complex assemblage of plants representing several floristic regions. Species characteristic of the Appalachian, Prairie, and Coastal Plain provinces of the North American Atlantic floristic region are most common; however, plants from the Rocky Mountain region and the Sonoran province of the Madrean region also are found in the state.

The vegetation of the state is equally diverse; 151 vegetation associations including forest, woodland, shrubland, and herbaceous associations are recognized currently in Oklahoma. This diversity of floristic and vegetation types is related to the state's unique position in North America, its ecological and geological diversity, and its environmental gradients in precipitation, temperature, elevation, topographic relief, and soils.