Rhododendron moupinense is one of the earliest flowering rhododendrons locally. Its delicate flowers are susceptible to hard rains, so a late January or February storm can leave this plant (specimen image) looking as if someone emptied a swimming pool onto it all at once.
Although some sites give it a common name of dwarf rhododendron, that name is applied to so many rhododendrons as to be functionally useless. Moupin rhododendron would be a better choice, referring to its occurrence in a mountainous region in Sichuan, China. Another alternative would be Baoxing rhododendron, as Baoxing County is the modern name for Moupin. This area of China, near the Tibet border, is famously known as the area where the European missionary and naturalist, Père Armand David, first encountered the (skin of a) giant panda. Incidentally, Rhododendron moupinense was named and described from specimens collected by David.
For a taxonomic description, see the Flora of China account for Rhododendron moupinense.