Creator
- Pintado, Vicente Sebastian1
- Pipkin1
- Pipkin, Beulah1
- Pittman, Flora Virginia, 1914-20051
- Plant System 1
- Plant, Rubie1
- Platt, Jan Kaminis (1936-)1
- Pleas, Charles Earl1
- Plourde, Jeffrey E.1
- Pohl, Frederik George, Jr. (1919-2013)1
- Polasek, Albin, 1879-19651
- Polk, James K.1
- Pomfrey, Mary Julia Thompson1
- Ponder, Clara M.1
- Ponder, Ernest Ayer, 1918-19981
- Pons, John O., 1927-20141
- Pope, Helen Smoyer1
- Pope, John1
- Por Larranaga (Havana, Cuba)1
- Porepp, Georg (1875-1942)1