1. Of or relating to or espousing operationalism
   "operationalist doctrine"

See also: operationalism

• genus Rattus
• genus Rauvolfia
• genus Rauwolfia
• genus Ravenala
• genus Recurvirostra
• genus Regalecus
• genus Regnellidium
• genus Regulus
• genus Reithrodontomys
• genus Remilegia
• genus Reseda
• genus Retama
• genus Reticulitermes
• genus Retrophyllum
• genus Rhagoletis
• genus Rhamnus
• genus Rhapis
• genus Rhea
• genus Rheum
• genus Rhexia
• genus Rhincodon
• genus Rhinoceros
• genus Rhinonicteris
• genus Rhinoptera
• genus Rhipsalis