All panicle branches are flexuous, and the lower branches occur in a whorl. Cobweb-like hairs occur at the base of the lemmas. Over 100 Kentucky bluegrass cultivars have been developed, resulting in a highly variable species. Canada bluegrass, a similar species found in the park, is distinguishable from Kentucky bluegrass vegetatively by its obviously flattened culm, compressed keel leaf sheaths, and more blue-green appearance. In all other respects, Canada bluegrass closely resembles Kentucky bluegrass.
Kentucky bluegrass is native to Europe, Eurasia, and possibly North America.
Some scientists theorize that Kentucky bluegrass may have migrated across the Bering Land Bridge 12,000 to 20,000 years ago. It was probably introduced to the east coast by early colonial settlers sometime after 1600 and spread westward by settlers. This species is now considered to be naturalized. Kentucky bluegrass is found throughout Canada, in each of the 50 states of the United States, and in Mexico. Kentucky bluegrass is adapted to a wide range of habitat conditions but favors moist habitats and can withstand temporary flooding.