- Irving, John Beaufain, 1800-1881
- Irving, Laurence 1895-1979
- Irving, M H
- Irving, Robert S
- Irving, Roland Duer, 1847-1888
- Irving, Stanley D
- Irving, Susan, ornithologist.
- Irving, Susan, ornithologist.
- Irving, Walter.
- Irving, Washington, 1783-1859
- Irvington Nurseries.
- Irvington Nursery.
- Irwin, A G
- Irwin, Bonnie Jean.
- Irwin, D
- Irwin, G J
- Irwin, H S
- Irwin, Henry
- Irwin, Howard S.
- Irwin, J Bruce
- Irwin, Jason T
- Irwin, Joshua J
- Irwin, Kelly J
- Irwin, Larry L. (Larry Lynn)
- Irwin, Marian
- Irwin, Mary
- Irwin, Michael E
- Irwin, Michael P. Stuart
- Irwin, Nancy
- Irwin, Roderick R
- Irwin, Roman J.
- Irwin, Stephen
- Irwin, Thomas H
- Irwin, Thomas S
- Irwin, William H.
- Irwin-Harrisons & Crosfield, inc.
- Irwin-Harrisons & Grosfield, inc.
- Irwin-Smith, Vera
- Irwn, Phil
- Isa Miranda, Agueda Veronica
- Isaac F. Tillinghast (Firm)
- Isaac Langley Williams (Firm)
- Isaac S. Hendrickson (Firm)
- Isaac, Andréia
- Isaac, Bonnie L.
- Isaac, Colin H. M.
- Isaac, Donald
- Isaac, Frances M
- Isaac, J J
- Isaac, John
- Isaac, Joseph A
- Isaac, Leo A. (Leo Anthony), 1892-1970
- Isaac, S
- Isaac, Sikuku
- Isaac, Victoria J.
- Isaac, William Edwyn, 1905-1995
- Isaaco, an African, Mungo Park's guide.
- Isaacs, E
- Isaacs, John D.
- Isaacs, S W
- Isaacsen, Adolph.
- Isaacson, H. E.
- Isaacson, Peter A.
- Isaac-Virgen, Maria de Lourdes
- Isaak, Mark
- Isabel, R.
- Isabelle, Marie.
- Isacch, Juan P
- Isaia, Marco
- Isaias, Rosy Mary dos Santos
- Isaji, Shinji
- Isakov, I︠U︡. A.
- Isaksson, Mats
- Isaldo, Diego I.
- Isaman, S. George
- Isarain Chávez, Eloy
- Isasawin, Siriwan
- Isasmendi, Sara Celina
- Isawumi, Moses A
- Isbell, Forest
- Isberg, Ericus.
- Isbrücker, I J H
- Ischinger, Lee S
- Ise, John, 1885-
- Ise, Yuji
- Iselin, Columbus O'Donnell, 1904-
- Isely, Duane
- Isely, Dwight, 1887-1974
- Isely, Frederick B., 1873-
- Isenberg, Irving H
- Isenberg, Tobias
- Isenbügel, E
- Isenflamm, Jacob Friedrich, 1726-1793
- Isensee, Ruth
- Iserhard, Cristiano Agra
- Isermann, Maike
- Isernhagen, Ingo
- Isert, Arthur
- Isert, Paul Erdmann, 1756-1789
- Iseto, Tohru
- Isgrove, Annie.
- Ish Pashuṭ.
- Ishak, Shah-Fadir
- Isham, Charles
- Ishara, Katia Losano
- Isherwood, I S
- Ishibashi, Satomi
- Ishibashi, Takeshi
- Ishibashi, Yasuyuki
- Ishida, Cecília M.
- Ishida, Hideki
- Ishida, Hiroshi
- Ishida, Keisuke
- Ishida, Teruo
- Ishida, Y. G.
- Ishida, Yoshiaki
- Ishigaki, Ken-Ichi
- Ishihara, Katsutoshi
- Ishihara, Teruhito
- Ishihara, Yoshimi
- Ishii, Iria Hiromi
- Ishii, Junko
- Ishii, Kazuhiro
- Ishii, Kiyoshi
- Ishii, Mamoru
- Ishii, Nobuo
- Ishii, Susumu
- Ishii, Teruhisa
- Ishijima, Sanae A
- Ishijima, Sumio
- Ishikawa, Atsushi
- Ishikawa, Carlos Massatoshi
- Ishikawa, Chiyomatsu 1860-
- Ishikawa, Hajime
- Ishikawa, Hiroshi
- Ishikawa, Kanga, 1781-1859
- Ishikawa, Kazuo
- Ishikawa, M.
- Ishikawa, Makiko
- Ishikawa, Márcia Mayumi.
- Ishikawa, Masamochi, 1754-1830
- Ishikawa, Noemia Kazue
- Ishikawa, Tadashi
- Ishikawa, Tairō, 1766-1817
- Ishikawa, Tatsuya
- Ishikawa, Tomoichi
- Ishikawa, Yuji
- Ishiki-Ishihara, Mario
- Ishikura, Masaharu
- Ishimatsu, Atsushi
- Ishimatsu, Sadamu
- Ishine, Mieko
- Ishino, MN.
- Ishiwata, Shigetane
- Ishizaka, Joji
- Ishizaki, Hironori
- Ishizaki, Kunihiro
- Ishizaki, Tsuyoshi
- Ishizuka, Hiroshi
- Ishizuka, Ineo
- Ishmael, William E.
- Isht, S Bsomrithipol
- Ishtiaq, Farah
- Ishwar, N M
- Isidor Bush & Co. (Firm)
- Isidoro, Nunzio
- Işık, Serap
- Isikov, V P
- Ising, Ernest H
- Isiordia-Aquino Néstor
- Isitt, Rylee
- Iskandar, Budhi Hascaryo
- Iskandar, Djoko T
- Iskandar, Johan
- Iskandarov, Abdulla
- Iskaros, Isaac Agaiby
- Isla, Federico I
- Islabão, Carolina Antuarte
- Islam, Kamal
- Islam, M. Zafar-ul
- Islam, Md
- Islam, Muhamma Anwarul
- Islam, Muhammad
- Islam, Muhammad
- Islam, Nurul
- Islam, R. M.
- Islam, S. Badrul.
- Islam, Touhidul
- Islam, Z
- Island Camellia Nursery,
- Island Curio (Company)
- Island Home Stock Farm (Grosse Ile, Mich.)
- Island Nurseries and Fruit Farm.
- Island Nursery,
- Island Peony Gardens.
- Island Seed Co.
- Islas-Espinoza Marina
- Islebe, Gerald A.
- Isler, Morton L
- Isler, Phyllis R
- Isles, A C
- Isleworth Nurseries.
- Islip, Adam, 1639
- Ismail, A Zainudin
- Ismail, A. L. S.
- Ismail, E H
- Ismail, G H
- Ismail, Îlhan Bayryam
- Ismail, Inche'
- Ismail, Ismail Mohamed Kamel
- Ismail, M M
- Ismail, M Mohamed
- Ismail, Mohamed Abdel-hehim, 1938-
- Ismail, Murni Azima
- Isman, Murray B
- Ismar-Rebitz, Stefanie M. H.
- Isnard, L C
- Isnard, Sandrine
- Isobe, Mitsui
- Isobe, Yū 1949-
- Isocrono, Deborah
- Isola, Daniela
- Isola, Tomas
- Isom, Billy G.
- Isomursu, Marja
- Isoré, Jacques, 1758-1839
- Isotti, Roberto
- Israel, Alvaro
- Israel, Michael L
- Israel, P
- Israel, W
- Israelsky, Merle C
- Israelson, Marguerite A.
- Israelson, Spencer.
- Issa, A A
- Issac, Golda
- Issajeff, Theodore Werner.
- Issaly, M
- Issartier, Henri, 1816-
- Issaverdens, James
- Issel, Arturo, 1842-1922
- Issel, Brigitte.
- Issel, Raffaele.
- Issel, Willi.
- Issembe, Y
- Issendorff, H. von
- Issia, Laura
- Issiki, Kleber
- Ista, Amanda
- Isthmian Canal Commission (U.S.)