• Carex aa Kom. accepted as Carex heleonastes subsp. heleonastes Ehrh. ex L.f.
• Carex abacta L.H.Bailey accepted as Carex michauxiana Boeckeler
• Carex abbreviata Prescott ex Boott accepted as Carex torreyi Tuck.
• Carex abdita E.P.Bicknell accepted as Carex umbellata Willd.
• Carex abitibiana Lepage
• Carex abjiciens Steud. accepted as Carex magellanica subsp. magellanica Lam.
• Carex ablata L.H.Bailey accepted as Carex luzulina var. ablata (L.H.Bailey) F.J.Herm.
• Carex ablata var. laxiuscula (Kük.) Sutô accepted as Carex argyrolepis Maxim. ex Franch. & Sav.
• Carex ablata var. luzuliformis L.H.Bailey accepted as Carex fissuricola Mack.
• Carex ablita Steud. (uncertain > unassessed)
• Carex abnormis (Rouy) Prain accepted as Carex mucronata All.
• Carex abnormis Rouy accepted as Carex mucronata All.
• Carex aboriginum M.E.Jones
• Carex abortiva Holmb.
• Carex abramsii Mack. accepted as Carex lemmonii W.Boott
• Carex abrupta Mack.
• Carex abscondita Mack.
• Carex abscondita var. abscondita Mack. accepted as Carex abscondita Mack.
• Carex abscondita var. glauca (Chapm.) Fernald accepted as Carex abscondita Mack.
• Carex abscondita var. rostellata Fernald accepted as Carex abscondita Mack.
• Carex absconditiformis Fernald accepted as Carex laxiculmis var. laxiculmis Schwein.
• Carex abyssinica Chiov. accepted as Carex phragmitoides Kük.
• Carex acaulis d'Urv.
• Carex accedens Holm accepted as Carex aperta Boott
• Carex accrescens Ohwi
• Carex accrescens var. sylvipaludosa Luchnik accepted as Carex accrescens Ohwi
• Carex acicularis Boott
• Carex acidicola Naczi
• Carex acocksii C.Archer
• Carex acrifolia V.I.Krecz. accepted as Carex pseudofoetida subsp. acrifolia (V.I.Krecz.) Kukkonen
• Carex acroandra Schur accepted as Carex repens Bellardi
• Carex acrogyna H.Lév. & Vaniot accepted as Carex ischnostachya var. fastigiata T.Koyama
• Carex acrolepis Ledeb. accepted as Carex gmelinii Hook. & Arn.
• Carex acrolepis Liebm. accepted as Carex polystachya var. polystachya Sw. ex Wahlenb.
• Carex acrophila S.T.Blake accepted as Carex bilateralis Hayata
• Carex acuminata Rchb. accepted as Carex evoluta Hartm.
• Carex acuminata Willd. accepted as Carex flacca subsp. erythrostachys (Hoppe) Holub
• Carex acuta Huds. accepted as Carex riparia Curtis
• Carex acuta L.
• Carex acuta L.H.Bailey accepted as Carex riparia Curtis
• Carex acuta f. amblylepis Peterm. accepted as Carex acuta L.
• Carex acuta f. badia Sanio accepted as Carex nigra subsp. nigra (L.) Reichard
• Carex acuta f. diluta Sanio accepted as Carex nigra subsp. nigra (L.) Reichard
• Carex acuta f. fluviatilis (Hartm.) Almq. accepted as Carex acuta L.
• Carex acuta f. graciliflora Legrand accepted as Carex acuta L.
• Carex acuta f. gracilis (Curtis) Sanio accepted as Carex acuta L.
• Carex acuta f. melanolepis Sanio accepted as Carex nigra subsp. nigra (L.) Reichard
• Carex acuta f. minor Boeckeler accepted as Carex turfosa Fr.
• Carex acuta f. pedicellata Peterm. accepted as Carex acuta L.
• Carex acuta f. personata (Fr.) Almq. accepted as Carex acuta L.
• Carex acuta f. prolixa (Fr.) Almq. accepted as Carex prolixa Fr.
• Carex acuta f. pseudosparganioides Čelak. accepted as Carex nigra subsp. nigra (L.) Reichard
• Carex acuta f. rigida Sanio accepted as Carex brunnea subsp. brunnea Thunb.
• Carex acuta f. ripensis Laest. accepted as Carex limula Fr.
• Carex acuta f. stygia Sanio accepted as Carex nigra subsp. nigra (L.) Reichard
• Carex acuta f. tourangiana (Boreau) Sanio accepted as Carex acuta L.
• Carex acuta f. touranginiana (Boreau) Sanio accepted as Carex acuta L.
• Carex acuta f. tricostata (Fr.) Almq. accepted as Carex acuta L.
• Carex acuta f. vaginata Peterm. accepted as Carex acuta L.
• Carex acuta f. zygostachya Rchb. accepted as Carex acuta L.
• Carex acuta subsp. angustifolia Čelak. accepted as Carex nigra subsp. nigra (L.) Reichard
• Carex acuta subsp. broteriana (Samp.) Rivas Mart. accepted as Carex reuteriana subsp. reuteriana Boiss.
• Carex acuta subsp. colorata F.Nyl. accepted as Carex acuta L.
• Carex acuta subsp. intermedia Čelak. accepted as Carex acuta L.
• Carex acuta subsp. mauritanica (Boiss. & Reut.) A.Asensi & B.Díez accepted as Carex reuteriana subsp. mauritanica (Boiss. & Reut.) Jim.Mejías & Luceño
• Carex acuta subsp. nigra (L.) Ehrh. accepted as Carex nigra (L.) Reichard
• Carex acuta subsp. nutans Čelak. accepted as Carex acuta L.
• Carex acuta subsp. personata (Fr.) P.Fourn. accepted as Carex acuta L.
• Carex acuta subsp. prolixa (Fr.) Nyman accepted as Carex prolixa Fr.
• Carex acuta subsp. reuteriana (Boiss.) Rivas Mart. & J.M.Pizarro accepted as Carex reuteriana Boiss.
• Carex acuta subsp. rufa (L.) Ehrh. accepted as Carex riparia Curtis
• Carex acuta subsp. ruffa (L.) Ehrh. accepted as Carex acuta L.
• Carex acuta subvar. graciliflora Legrand accepted as Carex acuta L.
• Carex acuta var. amblylepis (Peterm.) Nyman accepted as Carex acuta L.
• Carex acuta var. amblylepis Peterm. (uncertain > unassessed)
• Carex acuta var. angustifolia Čelak. accepted as Carex nigra subsp. nigra (L.) Reichard
• Carex acuta var. anomala Hartm. accepted as Carex acuta L.
• Carex acuta var. appendiculata Trautv. & C.A.Mey. accepted as Carex appendiculata (Trautv. & C.A.Mey.) Kük.
• Carex acuta var. broteriana (Samp.) Rivas Mart. accepted as Carex reuteriana Boiss.
• Carex acuta var. chlorostachya Rchb. accepted as Carex acuta L.
• Carex acuta var. chlorotica Čelak. accepted as Carex acuta L.
• Carex acuta var. colorata (F.Nyl.) Nyl. & Saelán accepted as Carex acuta L.
• Carex acuta var. dioica Peterm. accepted as Carex acuta L.
• Carex acuta var. elegans Wimm. accepted as Carex elytroides Fr.
• Carex acuta var. erecta Dewey accepted as Carex angustata Boott
• Carex acuta var. fluviatilis Hartm. accepted as Carex acuta L.
• Carex acuta var. graciliflora (Legrand) Rouy accepted as Carex acuta L.
• Carex acuta var. integrirostris Regel accepted as Carex acuta L.
• Carex acuta var. intermedia Čelak. accepted as Carex acuta L.
• Carex acuta var. longiglumis Cariot accepted as Carex brunnea subsp. brunnea Thunb.
• Carex acuta var. macrocarpa Čelak. accepted as Carex nigra subsp. nigra (L.) Reichard
• Carex acuta var. major Gray accepted as Carex acuta L.
• Carex acuta var. minor Boeckeler accepted as Carex limula Fr.
• Carex acuta var. minor Sw. accepted as Carex nigra subsp. nigra (L.) Reichard
• Carex acuta var. minor Trevir. accepted as Carex acuta L.
• Carex acuta var. moenchiana Nyman accepted as Carex acuta L.
• Carex acuta var. monstrosa Gray accepted as Carex acuta L.
• Carex acuta var. nardifolia Hartm. accepted as Carex acuta L.
• Carex acuta var. nervosa G.Mey. accepted as Carex trinervis Degl.
• Carex acuta var. nigra L. accepted as Carex nigra (L.) Reichard