Care - Cast
- Carex abacta L.H. Bailey
- Carex abbreviata Prescott
- Carex abdita E.P. Bicknell
- Carex ablata L.H. Bailey
- Carex aboriginum auct. non M.E. Jones, 1910
- Carex abrupta Mack.
- Carex abscondita Mack.
- Carex abscondita Mack. var. glauca (Chapm.) Fernald
- Carex abscondita Mack. var. glauca (Chapm.) Fernald
- Carex abscondita Mack. var. rostellata Fernald
- Carex absconditiformis Fernald
- Carex accedens T. Holm
- Carex acuta auct. non L.
- Carex acutiformis Ehrh.
- Carex acutina L.H. Bailey var. tenuior L.H. Bailey
- Carex acutinella Mack.
- Carex adelostoma Krecz.
- Carex adusta Boott
- Carex aenea Fernald
- Carex aestivalis M.A. Curtis ex A. Gray
- Carex aggregata Mack.
- Carex agrostoides Mack.
- Carex alata Torr.
- Carex albicans auct. non Willd. ex Spreng.
- Carex albicans Willd. ex Spreng.
- Carex albicans Willd. ex Spreng. var. albicans
- Carex albicans Willd. ex Spreng. var. australis (L.H. Bailey) J. Rettig
- Carex albicans Willd. ex Spreng. var. australis (L.H. Bailey) J. Rettig
- Carex albicans Willd. ex Spreng. var. emmonsii (Dewey ex Torr.) J. Rettig
- Carex albicans Willd. ex Spreng. var. emmonsii (Dewey ex Torr.) J. Rettig
- Carex albida L.H. Bailey
- Carex albolutescens Schwein.
- Carex albonigra Mack.
- Carex albursina Sheldon
- Carex allegheniensis Mack.
- Carex alligata Boott
- Carex alligata Boott var. degeneri R.W. Krauss
- Carex alma L.H. Bailey
- Carex alopecoidea Tuck.
- Carex amblyorhyncha Krecz.
