R. japonica

R. japonica may refer to:
 * Rana japonica, the Japanese brown frog, a frog species endemic to Japan
 * Ranzania japonica, a perennial herb species native to Honshū, Japan
 * Rhabdomastix japonica, a crane fly species in the genus Rhabdomastix
 * Rhamnus japonica, the Japanese buckthorn, a plant species in the genus Rhamnus
 * Rhomborrhina japonica, the drone beetle, a large beetle species
 * Rickettsia japonica, a bacterium species that causes the Japanese spotted fever
 * Rohdea japonica, the Nippon lily, sacred lily or Japanese sacred lily, a flowering plant species native from southwestern China to Japan
 * Roussoellopsis japonica, a fungus species

Synonyms

 * Reynoutria japonica, a synonym for Fallopia japonica, the Japanese knotweed, a large herbaceous perennial plant species native to Japan, China and Korea