THE TAXONOMY OF CAREX PETRICOSA (CYPERACEAE) AND RELATED SPECIES IN NORTH-AMERICA

In North America the Carex petricosa group has generally been consider ed to consist of three species, C. petricosa and C. franklinii in west ern Canada and Alaska, and C. misandroides in eastern Canada. In addit ion a number of other species and varieties have been described in the past fifty years, but these have generally not been given formal reco gnition by subsequent authors. A morphological study of herbarium spec imens of this group led to the conclusion that all of these taxa shoul d be treated as a single species. The western and eastern populations differed in the proportion of flowers that were distigmatic. Western p lants were mostly tristigmatic or had not more than 50% distigmatic fl owers. Eastern plants were mostly distigmatic or had more than 50% dis tigmatic flowers. Consequently two varieties were recognised in C. pet ricosa, var. petricosa from the west, and var. misandroides (Fernald) Boivin from the east.