Rhododendron japonicum
Rhododendron japonicum, the Japanese azalea, is a species of flowering plant in the family Ericaceae, native to Japan. A deciduous shrub reaching , it found in grasslands and open scrub, never in dense thickets or woodlands. It is very similar to Rhododendron molle, to the extent that its cultivars are customarily grouped with the cultivars of R.molle.

References

japonicum
Endemic flora of Japan
Plants described in 1908