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 See also Japonica (disambiguation)