Why is Carex the largest genus in the sedge family?

Carex is the largest genus in the Cyperaceae family, containing approximately 2,000 species. Its status as the largest genus is primarily attributed to its widespread distribution and ecological success across the globe.1

Unlike many other large genera within the sedge family, which are largely confined to tropical or warm temperate regions, Carex is found throughout the world, excluding only desert and semidesert areas. It exhibits significant species diversity in both the United States and across eastern Asia, from Siberia through China to Japan. While Carex is less common in tropical lowlands, it is often highly diverse in montane regions.1

This broad geographic range and ability to thrive in diverse environments—from temperate forests to wetlands—have contributed to the genus's extensive speciation.12