Rhodanthemum B.H.Wilcox, K.Bremer & Humphries
Riccaboni, Marco
Rich, William
Ritgen, Ferdinand August Maria Franz von
Robinson, Benjamin Lincoln
Robinson, Harold Ernest
Robson, Norman Keith Bonner
Rodionenko, Georgi Ivanovich
Roemer, Max Joseph
Roeper, Johannes August Christian
Roessler, Helmut
Rohrbach, Paul
Rohweder, Otto
Rolle, Friedrich
Ronniger, Karl(Carl)
Röschenbleck, Joachim
Rose, Joseph Nelson
Roth, Albrecht Wilhelm
Rothfels, Carl J.
Rothman, Göran
Roussel, Henri François Anne de
Rouy, Georges
Rowley, Gordon Douglas
Royle, John Forbes
Rudd, Velva Elaine
Ruiz López, Hipólito
Ruppius, Heinrich Bernhard
Ruprecht, Franz Josef Ivanovich
Rydberg, Per Axel
Salisbury. Richard Anthony