To determine whether Eleocharis tuberculosa var. pubnicoensis should be treated as a variety or as a form, herbarium material from throughout eastern North America and plants in southern Nova Scotian populations were examined. The variety pubnicoensis with smooth achene bristles was found to be confined to Great Pubnico Lake in Yarmouth County, southwestern Nova Scotia. Correlation analysis of population samples from 4 of 5 Nova Scotian lakes suggested that 4 of 5 characters associated with smooth bristles are actually a consequence of immaturity of fruiting spikes, and the remaining character is not significantly correlated. Discriminant analysis using the same characters of the same populations indicated that groupings based on bristle type were less significant and had higher misclassification rates than those based on spike maturity (based on disarticulation) and water depth. Due to a lack of confidence in a genetically based ecological and geographic integrity and a single morphological character, it seems most appropriate to treat pubnicoensis as a form.