From wikipedia: Rhododendron schlippenbachii (Royal Azalea) is a species of Rhododendron native to the Korean Peninsula and adjacent regions of Manchuria (Liaoning, Nei Mongol), Japan, and the Russian Far East. It is the dominant understory shrub in many Korean hillside forests, growing at 400-1500 m altitude.
It is a dense deciduous shrub growing to 4.5 m in height, but more commonly 1-2 m tall. The leaves are obovate, 4.5-7.5 cm long and 2.5-4.5 cm broad, with scattered glandular hairs. The flowers are white to pink, often with small red spots on the upper three petals; they are produced in late spring to early summer.
The scientific name schlippenbachii is derived from Baron von Schlippenbach, a Russian officer who collected the species in 1854.