- Plachetka, Mikuláš
- Plachno, Bartosz J
- Placho, Giorgio (Rome)
- Plachte, Frank Lothar, 1913-
- Plachter, H
- Plachter, Harald
- Plácido, Ricardo Antônio De Andrade
- Plácido-Silva, Alisson
- Placitus, Sextus, Papyriensis.
- Plack'S Nursery,
- Placzek, Christa
- Pladeck, Mildred
- Plageman, R. B. (Rudolph B.)
- Plagens, Michael Joseph, 1954-
- Plaia, P.
- Plăiaşu, Rodica
- Plain City Greenhouses.
- Plainer, R M
- Plainfield Nursery (Scotch Plains, N.J.)
- Plainfield Nursery (Scotch Plains, N.J.).
- Plainview Nursery.
- Plair, Bernadette L
- Plaitis, Wanda
- Plakhov, Nikita, 1758-1804
- Plakidas, J D
- Plakidas, John D
- Plakkhina, Evgeniia
- Plamboeck, Agneta H
- Plana, Jordi
- Plana, Jorge
- Plana-Fattori, Artemio
- Planas, Dolores
- Planas, Enric
- Planas, Eulalia
- Planas, Juan
- Planas, Miquel
- Planchard, F
- Planchon, G. (Gustave), 1833-1900
- Planchon, Jules-Emile, 1823-1888
- Planchon, Louis, 1858-1915
- Planchuelo, A M
- Planchuelo, Ana M.
- Planchuelo, Ana Maria
- Planck, R. J.
- Plane, M
- Planella, M. Teresa
- Planellas Giralt, José
- Planelles, Gabrielle
- Planer, Johann Jakob, 1743-1789
- Planer, Julius, 1827-1881
- Planes, S
- Planes, Serge
- Planet, Louis.
- Planetary Biodiversity Inventory (Project)
- Plangg, R.
- Plank, Andreas
- Plank, C. A.
- Plank, Elisha N.
- Plank, H. K. (Harold Kaufman), 1891-
- Plank, Heidi.
- Plank, Marlin E.
- Plank, Robert Northey.
- Plank, S
- Plankton Expedition 1889-
- Plannck, Stephan, active 15th century-
- Planning and Training Conference for Insect Nutrition and Rearing Excelsior Springs, Mo.) 1963-
- Planning and Training Conference for Insect Pathology and Biological Control Excelsior Springs, Mo.) 1964-
- Planning and Training Conference for Insect Population Suppression Memphis, Tenn.) 1965-
- Planoutene, M
- Planquette, P
- Plant Brothers.
- Plant Conservation Alliance.
- Plant Gene Resources of Canada. Seed Genebank.
- Plant Genetics and Germplasm Institute.
- Plant Materials Program (U.S.)
- Plant Nematology Workshop North Carolina State College) 1954-
- Plant Protection Laboratories (U.S.)
- Plant Research Centre (Canada)
- Plant Research Institute (Canada)
- Plant Seed Co.
- Plant Seed Co. (St. Louis, Mo)
- Plant Seed Company (Saint Louis, Mo.)
- Plant Seed Company.
- Plant Stress Laboratory.
- Plant World Association.
- Plant, Adrian R.
- Plant, Alfred.
- Plant, Colin W.
- Plant, Fred S.
- Plant, John
- Plant, R A
- Plant, R J
- Plantade, François de, 1670-1741
- Plantation Gardens (Firm),
- Plante, Émile.
- Plante, J
- Plante, J. B.
- Plante, Raphaël
- Plantentuin Meise
- Planters' Nurseries
- Planters' Nurseries.
- Planters Nursery Co. (Winfield, Kan.)
- Planters Nursery Company.
- Planters Seed Co. (Shreveport, La.)
- Planters Seed Co. (Springfield, Mo)
- Planters Seed Company.
- Planthon, M J-E
- Plantijnsche Drukkerij
- Plantin, Christophe, approximately 1520-1589
- Plantin, Martina 1550-1616
- Plantiniana (Ex Officina)
- Plantiniana, officina (Leiden)
- Planz, John V.
- Plascencia González, Héctor G.
- Plascencia-González A.
- Plascencia-González, Héctor G.
- Plasek, Vitezslav
- Plasencia, Edelquis
- Plaskett, J. S.
- Plasman, Charlie
- Plassan, Joseph-Raymond,
- Plassan, Pierre, 1751?-1810
- Plasse, C.
- Plasse, Chelle
- Plassmann, E
- Plassmann, Eberhard
- Plastina, Gabrielle
- Plastino, Estela M.
- Plastino, Estela Maria
- Plata Gómez, A.
- Plata, Camila
- Plata, Eimy Rivas
- Platania, Leonardo
- Platania, S P
- Plataniotis, Konstantinos N.
- Plata-Rosas, Luis J
- Plata-Rosas, Luis Javier
- Platas, G
- Platas, Javier González
- Plate, Ludwig, 1862-1937
- Platearius, Matthaeus, 1161
- Plateau, F
- Plateau, Félix Auguste Joseph, 1841-1911
- Plateau, M F
- Platel, Roland
- Platel, T G H
- Platell, M E
- Platen, Paul Louis, 1876-
- Platen, R
- Platen, Ralph
- Plath, H.
- Plath, Karl
- Plath, O E
- Plath, O. E. (Otto Emil), 1885-1940
- PLATHONG, JINTANA
- Plathong, Sakanan
- Platia, G
- Platia, Giuseppe
- Platner, G. R. (Gary R.)
- Platnick, Norman I.
- Platonov, Nikita G.
- Platonova, T. A.
- Platt & Barnes (Firm)
- Platt, A P
- Platt, Arnold William,
- Platt, Austin P
- Platt, Burton Coles
- Platt, C
- Platt, Charles A. (Charles Adams), 1861-1933
- Platt, Corry T
- Platt, E E
- Platt, Frank L., 1888-
- Platt, Frank S.
- Platt, Franklin
- Platt, H M
- Platt, Howard M
- Platt, J B
- Platt, Jerry L
- Platt, May
- Platt, Roy N
- Platt, Roy N., II,
- Platt, Rutherford
- Platt, S
- Platt, S G
- Platt, S W
- Platt, Steven G
- Platt, Thomas R
- Platt, Thomas Reid.
- Platt, Thomas.
- Platt, Trevor
- Platten, John.
- Platter, Franz, 1645-1711
- Plattes, Gabriel, fl 1638-1640
- Plattner, Hans
- Platts, J
- Platts, John, 1775-1837
- Platts, William S., 1928-
- Platvoet, D
- Platz, Bruce William.
- Platzer, Gregory P.
- Platzmann, Albert.
- Platzmann, Julius, 1832-1902
- Plaumann, Fritz
- Plaumann, Fritz.
- Plaut, I
- Plaut, Max
- Plavan, A. Acuña
- Player, Anne
- Player, Rodney L
- Playfair, Ernest, 1871-
- Playfair, G I
- Playfair, John, 1748-1819
- Playfair, Lyon Playfair, Baron, 1818-1898
- Playfair, R L
- Playfair, R. Lambert Sir, (Robert Lambert), 1828-1899
- Playford, G
- Playford, Geoffrey
- Playford, Julia
- Playford, P E
- Playford, Phillip
- Playford, Phillip E
- Plaza Benito, Antonio
- Plaza Seed Store.
- Plaza, E
- Plaza, Guido
- Plaza, Hugo Lea
- Plaza, J
- Plaza, Tarik G. D.
- Plaza-Buendía, Jorge
- Plazzi, Federico
- Pleas, E
- Pleasant Hill Nursery (Earlville, Iowa)
- Pleasant Hill Nursery Co.
- Pleasant Ridge Nurseries.
- Pleasant Run Nurseries.
- Pleasant Valley Farm.
- Pleasant Valley Farms,
- Pleasant Valley Nurseries and Seed Farms.
- Pleasant Valley Nurseries.
- Pleasant Valley Nursery (McMinnville, Tenn.)
- Pleasant Valley Seed Corn Farm.
- Pleasant View Farm.
- Pleasant View Gardens.
- Pleasant View Nurseries.
- Pleasant View Nursery
- Pleasants, Barbara Yohai
- Pleasants, J. Hall, jr.
- Plećaš, Milan
- Pledge, N S
- Pledge, Neville S