• Abronia acutalata Standl. accepted as Abronia umbellata Lam.
• Abronia alba Eastw.
• Abronia alpina Brandeg.
• Abronia ameliae Lundell
• Abronia ammophila Greene
• Abronia angustifolia Greene
• Abronia argillosa Welsh & Goodrich
• Abronia aurita Abrams, 1905
• Abronia bigelovii Heimerl
• Abronia breviflora Standl. accepted as Abronia umbellata Lam.
• Abronia carletonii Coult. & Fisher
• Abronia carnea Greene accepted as Tripterocalyx carnea (Greene) L.A. Gal.
• Abronia crux-maltae Kellogg accepted as Tripterocalyx crux-maltae (Kellogg) Standl.
• Abronia cycloptera Gray accepted as Tripterocalyx micranthus (Torr.) Hook.
• Abronia elliptica A. Nels.
• Abronia exalata Standl. accepted as Abronia turbinata Torr. ex S. Wats.
• Abronia fendleri Standl. accepted as Abronia ammophila Greene
• Abronia fragrans Nutt. ex Hook.
• Abronia gracilis Benth.
• Abronia insularis Standl.
• Abronia latifolia Eschsch.
• Abronia macrocarpa L.A. Gal.
• Abronia maritima Nutt. ex S. Wats.
• Abronia mellifera Dougl. ex Hook.
• Abronia micrantha Torr. accepted as Tripterocalyx micranthus (Torr.) Hook.
• Abronia minor Standl.
• Abronia nana S. Wats.
• Abronia neurophylla Standl.
• Abronia orbiculata Standl. accepted as Abronia turbinata Torr. ex S. Wats.
• Abronia pinetorum Abrams accepted as Abronia villosa S. Wats.
• Abronia platyphylla Standl.
• Abronia pogonantha Heimerl
• Abronia pumila Rydb. accepted as Abronia elliptica A. Nels.
• Abronia ramosa Standl. accepted as Abronia elliptica A. Nels.
• Abronia salsa Rydb. accepted as Abronia elliptica A. Nels.
• Abronia torreyi Standl. accepted as Abronia angustifolia Greene
• Abronia turbinata Torr. ex S. Wats.
• Abronia umbellata Lam.
• Abronia variabilis Standl. accepted as Abronia umbellata Lam.
• Abronia villosa S. Wats.
• Acanthocereus floridanus Small accepted as Acanthocereus tetragonus (Linnaeus) Hummelinck, 1938
• Acanthocereus pentagonus (L.) Britt. & Rose accepted as Acanthocereus tetragonus (Linnaeus) Hummelinck, 1938
• Acanthocereus tetragonus (Linnaeus) Hummelinck, 1938
• Acanthochiton wrightii Torr. accepted as Amaranthus acanthochiton Sauer
• Acanthogonum corrugatum Torr. accepted as Chorizanthe corrugata (Torr.) Torr. & Gray
• Acanthogonum polygonoides (Torr. & Gray) Goodman accepted as Chorizanthe polygonoides Torr. & Gray
• Acanthogonum rigidum Torr. accepted as Chorizanthe rigida (Torr.) Torr. & Gray
• Acetosa alpestris (Jacq.) A. Löve accepted as Rumex acetosa Linnaeus
• Acetosa gracilescens (Rech. f.) A. Löve & Evenson accepted as Rumex paucifolius Nutt.
• Acetosa oblongifolia (L.) A. & D. Löve accepted as Rumex obtusifolius Linnaeus
• Acetosella acetosella (L.) Small accepted as Rumex acetosella Linnaeus
• Acetosella corniculata (L.) Kuntze accepted as Oxalis corniculata Linnaeus
• Acetosella graminifolia (J.H. Rudolphi ex Lamb.) A. Löve accepted as Rumex graminifolius J.H. Rudolphi ex Lamb.
• Acetosella paucifolia (Nutt.) A. Löve accepted as Rumex paucifolius Nutt.
• Acetosella tenuifolia (Wallr.) A. Löve accepted as Rumex acetosella Linnaeus
• Acetosella vulgaris (Koch) Fourr. accepted as Rumex acetosella Linnaeus
• Achyranthes altissima Jacq. accepted as Chamissoa altissima (Jacq.) Kunth
• Achyranthes aquatica Roxburgh accepted as Centrostachys aquatica (Roxburgh) Wallich
• Achyranthes argentea Lam. accepted as Achyranthes aspera Linnaeus
• Achyranthes aspera Linnaeus
• Achyranthes atollensis St. John
• Achyranthes bettzichiana (Regel) Standl. accepted as Alternanthera bettzichiana (Regel) Voss
• Achyranthes bidentata Blume
• Achyranthes brasiliana (L.) Standl. accepted as Alternanthera brasiliana (Linnaeus) Kuntze, 1891
• Achyranthes ficoidea auct. non (L.) Lam. accepted as Alternanthera tenella Colla
• Achyranthes indica (L.) P. Mill. accepted as Achyranthes aspera Linnaeus
• Achyranthes ingramiana Standl. accepted as Alternanthera ingramiana (Standl.) Schinz
• Achyranthes japonica
• Achyranthes japonica (Miq.) Nakai
• Achyranthes leiantha (Seub.) Standl. accepted as Alternanthera pungens Kunth
• Achyranthes maritima (Mart.) Standl. accepted as Alternanthera maritima (Martius) A. Saint-Hilaire, 1833
• Achyranthes mutica Gray
• Achyranthes nelsonii St. John accepted as Achyranthes mutica Gray
• Achyranthes obtusifolia Lamarck accepted as Achyranthes aspera Linnaeus
• Achyranthes paronichyoides auct. non (L.) Lam. accepted as Alternanthera paronichyoides St.-Hil.
• Achyranthes peploides (Humb. & Bonpl. ex J.A. Schultes) Britt. & Wilson accepted as Alternanthera caracasana Kunth
• Achyranthes philoxeroides (Mart.) Standl. accepted as Alternanthera philoxeroides (Mart.) Griseb.
• Achyranthes portoricensis (Kuntze) Standl. accepted as Alternanthera crucis (Moq.) Boldingh
• Achyranthes prostrata Linnaeus accepted as Cyathula prostrata (L.) Blume
• Achyranthes ramosissima auct. non (Mart.) Standl. accepted as Alternanthera flavescens Kunth
• Achyranthes repens Linnaeus accepted as Alternanthera pungens Kunth
• Achyranthes sessilis (L.) Desf. ex Steud. accepted as Alternanthera sessilis (L.) R. Br. ex DC.
• Achyranthes splendens Mart. ex Moq.
• Achyronychia cooperi Torr. & Gray
• Acleisanthes acutifolia Standl.
• Acleisanthes anisophylla Gray
• Acleisanthes berlandieri Gray accepted as Acleisanthes obtusa (Choisy) Standl.
• Acleisanthes crassifolia Gray
• Acleisanthes greggii Standl. accepted as Acleisanthes obtusa (Choisy) Standl.
• Acleisanthes longiflora Gray
• Acleisanthes obtusa (Choisy) Standl.
• Acleisanthes wrightii (Gray) Benth. & Hook. f. ex Hemsl.
• Acnida alabamensis Standl. accepted as Amaranthus australis (A. Gray) J.D. Sauer, 1955
• Acnida altissima (Riddell) Moq. ex Standl. accepted as Amaranthus tuberculatus (Moq.) Sauer
• Acnida australis Gray accepted as Amaranthus australis (A. Gray) J.D. Sauer, 1955
• Acnida cannabina Linnaeus accepted as Amaranthus cannabinus (Linnaeus) J.D. Sauer, 1955
• Acnida concatenata (Moq.) Small accepted as Amaranthus tuberculatus (Moq.) Sauer
• Acnida cuspidata Bertero ex Spreng. accepted as Amaranthus australis (A. Gray) J.D. Sauer, 1955
• Acnida floridana S. Wats. accepted as Amaranthus floridanus (S. Wats.) Sauer
• Acnida subnuda (S. Wats.) Standl. accepted as Amaranthus tuberculatus (Moq.) Sauer