Contributions to the flora of the Red Lake Peatland, northern Minnesota, with special attention to Carex

The peatland has a flora that is relatively impoverished. In all, 331 plant taxa were recorded from the mire, including 195 vascular plants, 67 bryophytes and 69 lichen taxa. Members of the Cyperaceae account for 23% of the vascular flora, and the largest genus in the mire is Carex with 29 species. Each landform feature is distinctive in its floristic composition and the vascular and nonvascular taxa associated with the different physioographic features are discussed. This paper provides an account of Carex in the Red Lake peatland and discusses the differential response by members of the genus to gradients of nutrition, shading and hydrology. Some carices grow best under acid conditions, thus frequenting ombrotrophic and poor-gen sites, whereas other species grow best in rich-fen sites. Carex species useful in separating areas of embrotrophy from those of poor fen are indicated, as are those carices that serve as obligate rich-fen indicators. The floristic similarities between the Red Lake Peatland and 14 other peatlands in North America and northern Europe are discussed, and the ombrotrophic bog flora of the Red Lake Peatland is compared to the bog floras of the Hudson Bay lowlands and northern Fennoscandia.