• Juncus Linnaeus, 1753
• Juncus abjectus F.J. Herm. accepted as Juncus hemiendytus F.J. Herm.
• Juncus abortivus Chapm. accepted as Juncus pelocarpus E. Mey.
• Juncus achalensis Barros accepted as Juncus pallescens Lam.
• Juncus acicularis H. Roux accepted as Juncus sphaerocarpus Nees
• Juncus acuminatus Balb. accepted as Juncus arcticus Willd.
• Juncus acuminatus Michx.
• Juncus acuminatus Salzm. ex Kunth accepted as Juncus tingitanus Maire & Weiller
• Juncus acutangulus Buchenau accepted as Juncus capensis Thunb.
• Juncus acutiflorus Ehrh. ex Hoffm.
• Juncus acutissimus (Buchenau) Adamson accepted as Juncus inflexus Linnaeus
• Juncus acuto-maritimus E. Mey. accepted as Juncus littoralis C.A. Mey.
• Juncus acutus L.
• Juncus adriaticus Gand. accepted as Juncus littoralis C.A. Mey.
• Juncus adscendens Host accepted as Juncus articulatus Linnaeus
• Juncus aemulans Liebm.
• Juncus affinis Gaudin accepted as Juncus articulatus Linnaeus
• Juncus afghanicus Snogerup accepted as Juncus macrantherus V.I. Krecz. & Gontsch.
• Juncus agrostophyllus F. Muell. accepted as Juncus falcatus E. Mey.
• Juncus alatus Franch. & Sav.
• Juncus albescens (Lange) Fernald accepted as Juncus triglumis Linnaeus
• Juncus albescens Satake accepted as Juncus concinnus D. Don
• Juncus albicans Fernald accepted as Juncus dichotomus Elliott
• Juncus albidus Hoffm. accepted as Luzula luzuloides (Lam.) Dandy & E. Willm.
• Juncus alexandri L.A.S. Johnson
• Juncus allioides Franch.
• Juncus alpestris Bubani accepted as Juncus trifidus Linnaeus
• Juncus alpestris Hartm. accepted as Juncus alpinoarticulatus Chaix
• Juncus alpigenus K. Koch
• Juncus alpinoarticulatus Chaix
• Juncus alpinopilosus Chaix accepted as Luzula alpinopilosa (Chaix) Breistr.
• Juncus alpinus Vill. accepted as Juncus alpinoarticulatus Chaix
• Juncus altus Buchenau accepted as Juncus cephalotes Thunb.
• Juncus amabilis Edgar
• Juncus ambiguus Guss.
• Juncus amblyocarpus Rydb. accepted as Juncus articulatus Linnaeus
• Juncus amplifolius A. Camus
• Juncus amuricus (Maxim.) V.I. Krecz. & Gontsch.
• Juncus anatolicus Snogerup
• Juncus anceps Laharpe
• Juncus andersonii Buchenau
• Juncus andicola Hook. accepted as Juncus balticus Willd.
• Juncus andreanus Weath. accepted as Juncus dudleyi Wiegand
• Juncus angelisii Ten. accepted as Juncus inflexus Linnaeus
• Juncus angustifolius Wulfen accepted as Luzula luzuloides (Lam.) Dandy & E. Willm.
• Juncus anonymus Steud. accepted as Juncus capensis Thunb.
• Juncus antarcticus Hook. f.
• Juncus anthelatus (Wiegand) R.E. Brooks & Whittem.
• Juncus antonianus Steud. accepted as Juncus balticus Willd.
• Juncus apiculatus Adamson accepted as Juncus capensis Thunb.
• Juncus aquaticus (L.) All. accepted as Juncus articulatus Linnaeus
• Juncus arabicus (Asch. & Buchenau) Adamson accepted as Juncus rigidus Desf.
• Juncus arcticus Willd.
• Juncus arcuatus Wahlenb. accepted as Luzula arcuata (Wahlenb.) Sw.
• Juncus arequipensis Balslev accepted as Juncus cordobensis Barros
• Juncus arianus V.I. Krecz. accepted as Juncus fontanesii J. Gay ex Laharpe
• Juncus aridicola L.A.S. Johnson
• Juncus aristiflorus Clairv. accepted as Juncus articulatus Linnaeus
• Juncus aristulatus Michx. accepted as Juncus marginatus Rostk.
• Juncus arizonicus Wiegand accepted as Juncus interior Wiegand
• Juncus articulatus Linnaeus
• Juncus asper Engelm. accepted as Juncus caesariensis Coville
• Juncus asper Sauzé accepted as Juncus striatus Schousb. ex E. Mey.
• Juncus astreptus L.A.S. Johnson
• Juncus ater Rydb. accepted as Juncus balticus Willd.
• Juncus atlanticus Laharpe accepted as Juncus heterophyllus Dufour
• Juncus atratus Krock.
• Juncus atratus Lam. accepted as Juncus jacquinii Linnaeus
• Juncus atrofuscus Rupr. accepted as Juncus gerardii Loisel.
• Juncus atropurpureus Adamson accepted as Juncus capensis Thunb.
• Juncus attenuatus Viv. accepted as Juncus gerardii Loisel.
• Juncus aureus Pourr. accepted as Luzula lutea (All.) DC.
• Juncus auritus K.F. Wu accepted as Juncus wallichianus J. Gay ex Laharpe
• Juncus austerus Buchenau accepted as Juncus kraussii Hochst.
• Juncus australis Hook. f.
• Juncus bachitii Hochst. ex Steud. accepted as Juncus dregeanus Kunth
• Juncus badius Suksd. accepted as Juncus nevadensis S. Watson
• Juncus balansae Trab. accepted as Juncus punctorius L. f.
• Juncus balticus Willd.
• Juncus bassianus L.A.S. Johnson
• Juncus benghalensis Kunth
• Juncus beringensis Buchenau
• Juncus bhutanensis Satake accepted as Juncus leucomelas Royle ex D. Don
• Juncus bicephalus Viv. accepted as Juncus pygmaeus Rich. ex Thuill.
• Juncus bicornis Michx. accepted as Juncus tenuis Willd.
• Juncus biflorus Elliott accepted as Juncus marginatus Rostk.
• Juncus bifolius Hoppe accepted as Juncus subnodulosus Schrank
• Juncus biglumis Linnaeus
• Juncus biglumoides H. Hara
• Juncus biluoshanensis K.F. Wu accepted as Juncus spumosus Noltie
• Juncus bogotensis Humb. accepted as Juncus effusus Linnaeus
• Juncus bolanderi Engelm.
• Juncus bombonzanensis Satake accepted as Juncus prismatocarpus R. Br.
• Juncus bottnicus Wahlenb. accepted as Juncus gerardii Loisel.
• Juncus brachyanthus (Trab.) T. Durand & B.D. Jacks. accepted as Juncus fontanesii J. Gay ex Laharpe
• Juncus brachycarpus Engelm.
• Juncus brachycephalus (Engelm.) Buchenau
• Juncus brachyphyllus Wiegand
• Juncus brachyspathus Maxim.
• Juncus brachystigma Sam.