Provides an overview of 20 Sphagnum species known to occur in north-western Ontario, and includes two identification keys and additional descriptions that summarize each species' general appearance and habitat preferences. The resulting system for identifying Sphagnum species is intended for use as a field tool. Species descriptions include a short general description of each plant, a brief summary of its geographic distribution and common habitat relations, miscellaneous comments regarding other similar taxa or common associates in some habitats, a list of common names and taxonomic synonyms that might be used in other publications consulted during the identification process, and line illustrations of important taxonomic features referred to in the keys. Includes glossary.