In
Nepali R. dalhousiae is called
lahare chimal (). Hooker identified the species during his voyage to India and the Himalayas. The species was named after Lady Susan (née Hay) Dalhousie, the wife of the 10th
Earl of Dalhousie, James Andrew Broun-Ramsay, the
Governor-General of India at the time who travelled with Hooker at the start of the expedition out of India. However Hooker described
R. dalhousiae as “the noblest species of the whole race" and introduced it to England in 1850 where it was extremely popular when it first bloomed, three years after its arrival at
Dysart House in
Fife, Scotland. In adult plants, the leaves are 3 to 8 inches in length and up to 3 inches wide. When flowering, it produces two to six large flowers, typically around 4 inches in length. The colors of these flowers vary substantially from white to cream, pale yellow, or pale pink. The flowers have a lemon scent. Populations in northern Sikkim described by Pradhan & Lachungpa in
Sikkim-Himalayan Rhododendrons (1990) were reported as uniformly lemon-green, leading to the designation of the subspecies
R. dalhousiae var.
tashii named after the Sikkimese botanist Tse Ten Tashi. A number of varietals, such as
Rhododendron dalhousiae var.
rhabdotum, were previously believed to be separate species, but have since been identified as a varietal and is considered vulnerable. It is closely related to
Rhododendron lindleyi, although
R. lindleyi has slightly smaller flowers and is highly fragrant. The flowers of var.
rhabdotum are quite similar except for the five bright red stripes on each of the petals. In cultivation, var.
rhabdotum typically flowers later (mid- to late-summer) than
R. dalhousiae (late spring). == Ecology ==