Although fossil sedges are known from as early as the Eocene, they are as yet of little use in interpreting evolution in Cyperaceae because they are both fragmentary and apparently closely resemble modern groups. The rather uniform morphology of the nonreproductive parts of the plant body as well as the highly reduced flowers make deduction of evolutionary patterns from living sedges difficult. Thus, most theories on the evolution of the Cyperaceae at this point are derived from studies of the morphology and development of the spikelets. Current systems of classification of the Cyperaceae divide it into two to five subfamilies. ...(100 of 4369 words)