Poljakov, Petr Petrovich
Pomel, Auguste Nicolas
Pontedera, Giulio
Popov, Nikolai Petrovich
Porter, James Mark
Potztal, Eva Hedwig Ingeborg
Prado, Jefferson
Prantl, Karl Anton Eugen
Presl, Carl Borivoj
Presl, Jan Svatopluk
Prokhanov, Jaroslav Ivanovic (Yaroslav Ivanovich)
Pryor, Lindsay Dixon
Pursh, Frederick Traugott
Queiroz, Luciano Paganucci de
Quinn, Christopher John
Raamsdonk, Leonard Wouter Dirk van
Rabeler, Richard Kevin
Radić, Jure
Rafinesque-Schmaltz, Constantine Samuel
Rahn, Knud
Rauschert, Stephan
Raven, Peter Hamilton
Ravenna, Pierfelice
Razafimandimbison, Sylvain Georges
Rechinger, Karl Heinz
Rehder, Alfred
Reiche, Karl Friedrich
Reichenbach, Heinrich Gottlieb Ludwig
Reichenbach, Heinrich Gustav
Reveal, James Lauritz