Results obtained in studies of grassland myxomycetes (plasmodial slime molds or myxogastrids), based on the species appearing in moist-chamber cultures, have indicated that forb microhabitats yield considerably more collections than grass microhabitats. We experimentally evaluated this pattern at the Tall Grass Prairie Preserve in Oklahoma by using litterbags prepared with autoclaved samples of grasses and forbs. We obtained a total of 162 collections representing 20 species; Perichaena pedata and Diderma effusum were the dominant species present. Total number of collections, species richness, and species diversity were significantly higher for forb microhabitats when compared to grass microhabitats. These results corroborate previous reports and demonstrate the utility of using litterbags as an experimental approach to assess myxomycete diversity and to confirm or refute observations from previous ecological studies.