The second revised edition of this manual aims at providing students and less experienced professional aquatic biologists with a key to identify some to the more commonly encountered aquatic freshwater algal genera of the United States. In response to reviewers comments, a brief section on diatoms, a section providing a number of possible of dispositions of the genera into a taxonomic hierarchy and a brief glossary of technical terms have been added in this revised edition. A number of nomenclatural changes is reflected as well. Keys, representative illustrations and general ecological notes are provided for some 300 genera, excluding the diatoms (except for a brief section on them). The keys are based on features observable in freshly collected material. Audience: students, professional aquatic biologists, anybody interested in the phycology of the freshwaters of North Americaweiterlesen