'Plains' Bluestem (released in 1972) a composite of 30 similar looking accessions collected from six different countries. The composite of so many different accessions enables it to be widely adapted across the Southern Great Plains.
'WW-Spar' (released in 1981) an original component of 'Plains'. It has its origin in Pakistan and is more drought tolerant than the other lines making up 'Plains'.
'WW-Ironmaster' (released in 1987) was specifically selected based on its performance on iron-deficient soils typical of high pH soils. It is adapted to soil pHs of 7.4 to 8.4 but is less productive than 'WW-Spar' and 'Plains'.
'Caucasian' Bluestem (introduced in 1929) has a higher degree of winter tolerance than the other cultivars and produces better tonnage under favorable conditions. 'Caucasian' does not perform as well under drought conditions..
'WW-B.Dahl' (jointly released in 1994 by Texas Tech, TAEX, and the Soil Conservation Service in 1994) the most recent release of Old World Bluestems and originated in India. It is typically more productive, has broader leaves, slightly more palatable,, and matures later than other cultivars. Cold tolerance is not as good as the other cultivars and best adapted to southern Oklahoma and Texas.