The types and distribution of silica bodies (opaline phytoliths) of 26 species of native and introduced grasses of the range grasslands of southern Alberta are described. The genera examined are Bromus, Festuca, Poa, Koeleria, Deschampsia, Calamagrostis, Phleum, Agropyron, Elymus, Stipa, Danthonia, and Bouteloua. Scale drawings of representative silica bodies for each genus are provided.The observations are discussed in relation to grass taxonomy, and to the overall role of silica in grasses.