I often describe the learning curve for algal taxonomy as an overhanging ice cliff, nearly unassailable to students who are unfamiliar with algal divisions and the peculiarities of dichotomous keys. Dillard’s introductory text, Common Freshwater Algae of the United States, provides a great introduction to algal taxonomy, with clear, simple choices that take students to eight sections separated by easily observed morphological differences (e.g., algae unicellular, alga not unicellular). Keys, illustrations, and ecological notes are provided for about 300 genera.