Greens-type Poa annua L. has been noted as a species of turfgrass with great utility for golf course putting greens since the early 1920s. Nevertheless in the 80 years to present date, there has never been a stable, commercially available greens-type P. annua variety released to the market. Within the species P. annua, there exists a range of life history biotypes from robust annual types to dwarf perennial greens-types. Past research has documented that the traits which are unique to greens-type P. annua; stunted stem, leaf, and flower development, and delayed flower induction, have high broad-sense heritability and are linked. Our most recent research concurs with these prior findings, and suggests that the greens-type phenotype is regulated by a single genetic mechanism. However, greens-type x greens-type crosses have yielded somatic and germinal reversions to the annual-type morphology. Evidence will be presented that eliminates the possibility of out-crossing contamination and gene complementation, thus refuting a mendelian mechanism for these traits. Along with additional morphological, genetic, and molecular analysis, the results imply a non-mendelian, epigenetic mechanism that regulates the adaptative evolution of the greens-type Poa annua L.