• Rhynchospora aberrans C.B.Clarke
• Rhynchospora acanthoma A.C.Araújo & Longhi-Wagner
• Rhynchospora adscendens C.B.Clarke accepted as Rhynchospora candida (Nees) Boeckeler
• Rhynchospora adulta Schltdl. accepted as Rhynchospora polyphylla (Vahl) Vahl
• Rhynchospora affinis W.Fitzg.
• Rhynchospora africana Cherm. accepted as Rhynchospora angolensis Turrill
• Rhynchospora agostiniana T.Koyama
• Rhynchospora alba (L.) Vahl
• Rhynchospora alba f. alba (L.) Vahl accepted as Rhynchospora alba (L.) Vahl
• Rhynchospora alba f. laeviseta Gale accepted as Rhynchospora alba (L.) Vahl
• Rhynchospora alba var. fusca (L.) Pursh accepted as Rhynchospora fusca (L.) W.T.Aiton
• Rhynchospora alba var. fusca (L.) Vahl accepted as Rhynchospora fusca (L.) W.T.Aiton
• Rhynchospora alba var. kiusiana Makino accepted as Rhynchospora alba (L.) Vahl
• Rhynchospora alba var. macra C.B.Clarke ex Britton accepted as Rhynchospora macra (C.B.Clarke ex Britton) Small
• Rhynchospora alba var. meridiana H.Pfeiff. (uncertain > unassessed)
• Rhynchospora albescens (Miq.) Kük.
• Rhynchospora albiceps Kunth
• Rhynchospora albida (Nees) Boeckeler
• Rhynchospora albobracteata A.C.Araújo
• Rhynchospora albomarginata Kük.
• Rhynchospora albotuberculata Kük.
• Rhynchospora almensis D.A.Simpson
• Rhynchospora alpina (R.Br.) Spreng. accepted as Carpha alpina R.Br.
• Rhynchospora alpina Palla accepted as Rhynchospora biflora Boeckeler
• Rhynchospora alta Boeckeler accepted as Rhynchospora loefgrenii Boeckeler
• Rhynchospora amazonica Poepp. ex Kunth
• Rhynchospora amazonica subsp. amazonica Poepp. ex Kunth
• Rhynchospora amazonica subsp. guianensis (Kük.) T.Koyama accepted as Rhynchospora rionegrensis P.Weber & W.W.Thomas
• Rhynchospora amazonica var. guianensis Kük. accepted as Rhynchospora rionegrensis P.Weber & W.W.Thomas
• Rhynchospora andina Kük. accepted as Rhynchospora caracasana (Kunth) Boeckeler
• Rhynchospora andresii Gómez-Laur.
• Rhynchospora angolensis Turrill
• Rhynchospora angosturensis W.W.Thomas
• Rhynchospora angusta (Gale) Sorrie, LeBlond & Weakley
• Rhynchospora angustifolia Palla
• Rhynchospora angustipaniculata M.T.Strong
• Rhynchospora anomala Steud. accepted as Fimbristylis fusca (Nees) Benth. ex C.B.Clarke
• Rhynchospora arechavaletae Boeckeler accepted as Rhynchospora holoschoenoides (Rich.) Herter
• Rhynchospora arechavaletae f. pleiocephala Osten accepted as Rhynchospora holoschoenoides (Rich.) Herter
• Rhynchospora arechavaletae var. ostenii (Kük.) Kük. accepted as Rhynchospora holoschoenoides (Rich.) Herter
• Rhynchospora arenicola Uittien
• Rhynchospora argentea Standl.
• Rhynchospora aripoensis Britton
• Rhynchospora aristata Boeckeler
• Rhynchospora aristata var. aristata Boeckeler
• Rhynchospora aristata var. brevifoliata Kük. accepted as Rhynchospora brevifoliata (Kük.) Greuter & R.Rankin
• Rhynchospora aristata var. cruegeriana (Boeckeler) Kük. accepted as Rhynchospora longiflora C.Presl
• Rhynchospora aristata var. fuertesii (Urb.) Kük. accepted as Rhynchospora aristata var. aristata Boeckeler
• Rhynchospora aristata var. immensa (Kük.) Kük. accepted as Rhynchospora immensa Kük.
• Rhynchospora aristata var. latilaminata Kük. accepted as Rhynchospora aristata var. aristata Boeckeler
• Rhynchospora aristata var. moritziana (Boeckeler) Kük.
• Rhynchospora aristata var. suberecta Kük.
• Rhynchospora armerioides J.Presl & C.Presl
• Rhynchospora arrojadii H.Pfeiff. (uncertain > unassessed)
• Rhynchospora articulata (Roxb.) Schult. accepted as Rhynchospora corymbosa (L.) Britton
• Rhynchospora arundinacea Boeckeler accepted as Rhynchospora exaltata Kunth
• Rhynchospora asperula (Nees) Steud.
• Rhynchospora atlantica W.W.Thomas
• Rhynchospora aurea Vahl accepted as Rhynchospora corymbosa (L.) Britton
• Rhynchospora aurea f. florida (Rudge) Lindm. accepted as Rhynchospora corymbosa (L.) Britton
• Rhynchospora aureiformis C.B.Clarke accepted as Rhynchospora velutina (Kunth) Boeckeler
• Rhynchospora auriculata Boeckeler accepted as Rhynchospora albiceps Kunth
• Rhynchospora austrobahiensis W.W.Thomas
• Rhynchospora avenacea (R.Br.) Spreng. accepted as Cyathochaeta avenacea (R.Br.) Benth.
• Rhynchospora axillaris (Lam.) Britton accepted as Rhynchospora glomerata (L.) Vahl
• Rhynchospora axillaris var. microcephala Britton accepted as Rhynchospora microcephala (Britton) Britton
• Rhynchospora ayangannensis M.T.Strong
• Rhynchospora bahamensis Britton accepted as Rhynchospora lindeniana Griseb.
• Rhynchospora bahiensis Steud. accepted as Rhynchospora barbata (Vahl) Kunth
• Rhynchospora baileyi Britton accepted as Rhynchospora albomarginata Kük.
• Rhynchospora bakhuisensis M.T.Strong
• Rhynchospora baldwinii A.Gray
• Rhynchospora barbata (Vahl) Kunth
• Rhynchospora barbata var. bahiensis (Steud.) Boeckeler accepted as Rhynchospora barbata (Vahl) Kunth
• Rhynchospora barbata var. glabra Maury accepted as Rhynchospora barbata (Vahl) Kunth
• Rhynchospora barrosiana Guagl.
• Rhynchospora belizensis Naczi & Silva Filho
• Rhynchospora berteroana Boeckeler accepted as Rhynchospora berteroi (Spreng.) C.B.Clarke
• Rhynchospora berteroi (Spreng.) C.B.Clarke
• Rhynchospora beyrichii (Nees) Steud. accepted as Rhynchospora exaltata Kunth
• Rhynchospora biceps Torr. ex A.Gray accepted as Rhynchospora cephalantha A.Gray
• Rhynchospora biflora Boeckeler
• Rhynchospora biflora var. cryptantha (C.B.Clarke) Kük. accepted as Rhynchospora biflora Boeckeler
• Rhynchospora binervis Sieber ex C.Presl accepted as Hypolytrum mauritianum Nees ex Kunth
• Rhynchospora blauneri Britton accepted as Rhynchospora brachychaeta C.Wright
• Rhynchospora blepharophora (J.Presl & C.Presl) H.Pfeiff.
• Rhynchospora boeckeleriana Silva Filho & Boldrini
• Rhynchospora boivinii Boeckeler
• Rhynchospora bolivarana Steyerm.
• Rhynchospora boliviensis C.B.Clarke
• Rhynchospora boninensis Nakai ex Tuyama
• Rhynchospora borinquensis Britton accepted as Rhynchospora marisculus Lindl. & Nees
• Rhynchospora brachychaeta C.Wright
• Rhynchospora bracteovillosa A.C.Araújo & W.W.Thomas
• Rhynchospora bradei (R.Gross) W.W.Thomas
• Rhynchospora brasiliensis Boeckeler
• Rhynchospora brevifoliata (Kük.) Greuter & R.Rankin
• Rhynchospora brevirostris Griseb.
• Rhynchospora brevirostris var. clarkei (Rose) Kük. accepted as Rhynchospora brevirostris Griseb.
• Rhynchospora brevirostris var. truncata Kük. accepted as Rhynchospora brevirostris Griseb.