Schellenberg, M. P., Biligetu, B., McLeod, G. J. and Wang, Z. 2012. Phenotypic variation of side-oats grama grass [Bouteloua curtipendula (Michx.) Torr.] collections from the Canadian prairie. Can. J. Plant Sci. 92: 1043-1048. Native prairie grasses are adapted to local climates and have the potential for development as forage grass cultivars for semiarid environments. Side-oats grama grass [Bouteloua curtipendula (Michx.) Torr.] is a drought-tolerant grass with desirable forage characteristics, and is distributed across the Canadian prairies and throughout the Great Plains. Understanding ecotypic variability of this species is a prerequisite for developing populations suitable for drier regions of western Canada. A randomized complete block field plot was established using nine seed collections from Manitoba and Saskatchewan in 2006 near Swift Current (lat. 50°25′N, long. 107°44′W), Canada. Seed yield, tiller number, plant height, foliage diameter, and days to flower of individual plants were measured for each collection in the summers of 2007 and 2010. The Sidney and Wolseley collections had taller plants with greater basal diameter. Plants from these two collections also had higher tiller number, and required fewer days to reach flowering stage. However, there was no clear ranking of these variables among other collections. Averaged flowering date was Aug. 15 for Alexander, Sidney, and Wolseley collections, Aug. 21 for Wellwood, Glenboro, and Pratt collections, and Aug. 26 for Minto and Coulter collections, respectively. Taller plants with greater tiller number for the Sidney and Wolseley collections showed a potential for further cultivar development.