Carex hermannii (Cyperaceae), a new species from Mexico,with comments on related species at high altitudes in middle America

Carex hermannii, a new species known only from a few populations on large volcanic mountains on the Puebla-México state border, central Mexico, is described, illustrated and compared with its nearest relative,C. cuchumatanensis of Guatemala. Both these species have been confused until now with the more distantly relatedC. endlichii. Morphological comparisons ofC. hermannii, C. cuchumatanensis andC. endlichii confirm the distinctiveness of these species.