Variability of Bluegrass (Poa) in Siberia

Siberian bluegrass (Poa) includes a number of polymorphic species such as P. arctica s.l., P. nemoralis s.l., P. palustris s.l., P. pratensis s.l., P. sibirica s.l., and P. smirnovii s.l., plus numerous hybrids and purported derivatives (e.g., P. attenuata s.l., P. glauca s.l., P. urssulensis s.l.). In Siberia Poa is represented by morphologically isolated species and hybrid-apomictic complexes, including both distinct species and taxonomic groups of obscure rank. Section Stenopoa is especially rich in these complexes. Most of the key morphological characters used in the taxonomy of bluegrass vary as much within populations as among populations and thus do not support recognition of some previously described taxa. It is likely that karyological or other genetic data would identify regionally distinct taxa. The area of the greatest intraspecific variation of Poa in Siberia is the Altai Mountain region based on analyses of distribution and morphology. Geography must be considered during conservation planning activities to avoid impacting locally adapted and morphologically divergent populations of broadly distributed species.