- Academia Caesareo-Leopoldina Naturae Curiosorum.
- Academia Canaria de Ciencias.
- Academia Colombiana de Ciencias Exactas, Físicas y Naturales,
- Academia das Ciências de Lisboa.
- Academia De Ciencias Físicas, Matemáticas Y Naturales (Venezuela)
- Academia de Ciencias Médicas, Físicas y Naturales de La Habana.
- Academia Médico-Quirúrgica (Puebla Mexico)
- Academia Nacional de Ciencias (Córdoba, Argentina)
- Academia Nacional de Ciencias Antonio Alzate, Mexico
- Academia Nacional de Ciencias en Córdoba.
- Academia Nacional de Ciencias Exactas (Argentina)
- Academia Nacional de Medicina (México)
- Academia Real das Sciencias de Lisboa.
- Academia Republicii Socialiste România.
- Academia Rheno-Traiectinae.
- Académie d'Amiens
- Académie de Dijon.
- Académie de La Rochelle. Section des sciences naturelles.
- Académie de Médicine (France)
- Académie de Reims.
- Académie des sciences (France)
- Académie Des Sciences (France). Commission du passage de Venus, 1874.
- Academie des Sciences et Lettres de Montpellier.
- Académie des sciences, agriculture, arts & belles-lettres dAix
- Académie des sciences, arts et belles lettres de Dijon (France)
- Académie des sciences, arts et belles-lettres de Caen
- Académie des sciences, belles lettres & arts de Rouen
- Académie des sciences, belles-lettres et arts de Lyon.
- Académie des sciences, belles-lettres et arts de Savoie
- Académie des sciences, inscriptions et belles-lettres de Toulouse.
- Académie d'horticulture (Paris, France)
- Académie impériale des sciences, arts et belles-lettres de Caen
- Académie internationale de botanique.
- Académie internationale de géographie botanique.
- Académie internationale d'histoire des sciences
- Académie malgache.
- Académie nationale de Reims (France)
- Académie nationale des sciences, belles-lettres et arts de Bordeaux
- Académie royale des sciences (France)
- Académie royale des sciences, des lettres et des beaux-arts de Belgique.
- Académie royale des sciences, des lettres et des beaux-arts de Belgique. Classe des sciences.
- Academy Nursery.
- Academy of Natural Sciences of Philadelphia.
- Academy of Natural Sciences of Philadelphia. Conchological Section.
- Academy of Natural Sciences of Philadelphia. Department of Malacology.
- Academy of Natural Sciences of Philadelphia. Department of Mollusks
- Academy of Natural Sciences of Philadelphia. Entomological Section
- Academy of Natural Sciences of Philadelphia. Library
- Academy of Science and Letters of Sioux City (Iowa)
- Academy of Science of St. Louis.
- Acadia Farms
- Acadian Entomological Society.
- Acaeva, Maret
- Acal, Dale Ann P.
- Ačanski, Jelena
- Acar, Ismail
- Accacio, Gustavo Mattos
- Accademia degli Aspiranti Naturalisti.
- Accademia del cimento (Florence, Italy)
- Accademia della Crusca,
- Accademia delle scienze dell'Istituto di Bologna.
- Accademia delle Scienze di Napoli
- Accademia delle Scienze di Siena.
- Accademia delle scienze di Torino
- Accademia delle Scienze Matematiche Scienze Naturali e Scienze Morali(Napoli)
- Accademia di agricoltura, arti e commercio di Verona.
- Accademia di Padova.
- Accademia di scienze, lettere e arti di Palermo.
- Accademia di scienze, lettere ed arti di Padova.
- Accademia di scienze, lettere, agricultura, ed arti.
- Accademia gioenia di scienze naturali in Catania.
- Accademia Imperiale delle Scienze e Belle Arti(Genoa)
- Accademia Italiana di Scienze. Lettere ed Arti, Livorno.
- Accademia nazionale dei Lincei
- Accademia nazionale dei Lincei. Classe di scienze fisiche, matematiche e naturali.
- Accademia Pontaniana.
- Accademia Pontificia dei Nuovi Lincei.
- Accardo Filho, Marco Antonio Palomares
- Accattoli, Cecilia
- Acciaresi, Horacio A
- Acciavatti, Robert E.
- Accino, R Grandfils
- Accioly, Miguel da Costa
- Acclimatisation Society of Victoria.
- Acclimatisations Verein.
- Accomac Co. (Va.)
- Accomac Nurseries.
- Accomack Nurseries.
- Acconcia, Raffaele
- Accorsi, Walter Radamés
- Ace Nursery,
- Acebes Ginovés, Juan Ramón
- Acebes, Pablo
- Acebey, Amparo.
- Acedo, Carmen
- Acedo, Marta Sansón
- Acedo-Félix Evelia
- Aceituno Mata, Laura
- Acel, Anagela Maria
- Acerbi, Giuseppe, 1773-1846
- Acero Pizarro, Arturo, 1954-
- Acero, Tomás
- Acevedo M., Gilbert
- Acevedo, Aldemar A.
- Acevedo, Daniela
- Acevedo, Edmundo
- Acevedo, Gustavo D
- Acevedo, Jesús
- Acevedo, Jorge A.
- Acevedo, Kelly
- Acevedo, M
- Acevedo, Patricia A.
- Acevedo, Patricio
- Acevedo, Romina F
- Acevedo, Rubén
- Acevedo-Cervantes, Alejandro
- Acevedo-Charry, Orlando A.
- Acevedo-Rodríguez, Pedro
- Acevedo-Rosas, Raul
- Aceves De Alba, Jorge
- Aceves, G.
- Aceves-Aparicio, Alfonso
- Aceves-Medina, Gerardo
- Acha, Eduardo M
- Acha, Marcelo
- Achá, Serena
- Achakzai, AKK
- Achalme
- Achard, J
- Achard, Julien.
- Achard, Louis Amédée Eugène, 1814-1875
- Acharius, Erik, 1757-1819
- Acharji, M N
- Acharjyo, L N
- Acharya, B C
- Acharya, B K
- Acharya, Chirag A
- Acharya, Hari Narayan G.
- Acharya, Krishnendu
- Acharya, Kumud
- Acharya, Laxmikanta
- Acharya, Raju
- Achaval, A.
- Achaval, Federico
- Achaval, M.
- Achberger, E C
- Ache, B W
- Ache, Barry W
- Acheampong, Susanna
- Achelis, George.
- Achepohl, Ludwig.
- Achermann, J
- Achermann, M
- Acheroy, Marc
- Acheson, Frederick
- Achhal El Kadmiri, Ahmed
- Achille, Frédéric
- Achilles, A.
- Achilles, C.,
- Achilles, C., active 1878-
- Achinelly, María Fernanda
- Achintre, A. (Auguste), 1834-1886
- Achiorno, Cecilia L.
- Achituv, Y
- Achkar, Samira M.
- Achmadi, Anang Setiawan,
- Achmann, Roland
- Achorn, John Warren
- Achoundong, Gaston
- Achrem, Magdalena
- Achtelig, Michael
- Achterberg, C. van
- Achtermann, C.
- Achuff, P. L.
- Achyar, Afifatul
- Achyuthan, N S
- Acid Deposition Research Program.
- Acidic Precipitation in Ontario Study
- Açik, Sermin
- Acinas, Silvia G
- Acioli, Agno Nonato Serrão
- Acioli, Ellen Cristina Serrão
- Acioli, TC.
- Acker, C.
- Acker, Geraldine.
- Acker, S. L.
- Acker, Steven A
- Ackerfield, Jennifer
- Ackerknecht, Erwin H
- Ackerly, Spafford C
- Ackerman Lithr.,
- Ackerman Nurseries.
- Ackerman, A.
- Ackerman, A. J. (Arthur John), 1889-1937
- Ackerman, Drew
- Ackerman, Edward A. (Edward Augustus), 1911-1973
- Ackerman, Eugene, 1920-
- Ackerman, J. E.
- Ackerman, James
- Ackerman, James
- Ackerman, James D
- Ackerman, James, 1815 or 16-1864
- Ackerman, Joseph.
- Ackerman, Joshua T
- Ackerman, Kim
- Ackerman, Madison R.
- Ackerman, William L.
- Ackermann, Gabriela.
- Ackermann, Gordon
- Ackermann, Johann Christian Gottlieb, 1756-1801
- Ackermann, Markus
- Ackermann, Werner
- Ackermann-Salisch.
- Ackert, James E. (James Edward), 1879-1969
- Ackery, Phillip Ronald
- Ackland, D M
- Ackland, David M.
- Ackroyd, S
- Acksell, Pehr Magnus.
- Acland, Henry W. (Henry Wentworth), 1815-1900
- Acland, R D
- Acland, Thomas D.
- Acloque, A. (Alexandre), 1871-1908
- Acloque, Alexandre.
- Acme Berry Gardens.
- Acme Seed Company (Dayton, Ohio)
- Acocks, J P H
- Acola, Mescel S.
- Aconiti Mandolini, Luca
- Acorn, John H.
- Acorn, Robert C.
- Acosta Cantillo, Félix
- Acosta Carrazco, Héctor Iván
- Acosta Hospitaleche, Carolina
- Acosta Solís, Misael
- ACOSTA V., Emilio
- Acosta Velázquez, Joanna
- Acosta, AA
- Acosta, Alberto
- Acosta, Alejandro
- Acosta, Alexis
- Acosta, Alicia
- Acosta, Allan J., 1924-
- Acosta, Amilvia
- Acosta, Ana M
- Acosta, C.
- Acosta, Charles A.
- Acosta, Cristóbal, approximately 1515-approximately 1592
- Acosta, Joaquín, 1800-1852
- Acosta, José de, 1540-1600