This species is closely related to R. minus (punctatum) and was identified with it as a variety until 1912, when Dr Rehder gave it its present name. It was orginally introduced to England by John Fraser in 1811, but, according to Rehder, was subsequently lost to cultivation, not being seen again in this country until reintroduced from H. P. Kelsey’s nursery, Carolina, in 1895. It is an evergreen shrub of more compact habit than the true R. minus, young shoots scaly. Leaves elliptic to elliptic-obovate, broadly wedge-shaped at the base, tapered at the apex to an often bluntish point, 1 to 31⁄2 in. long, 1⁄2 to 13⁄4 in. wide, glossy green and soon glabrous above; densely covered with ultimately dark scales beneath; midrib yellowish; stalk stout, 1⁄8 to 1⁄3 in. long. Flowers four to ten in a terminal truss, opening in May. Corolla five-lobed, about 11⁄2 in. wide, pale rosy purple, faintly or not at all spotted, the lobes rather longer than the tube. Stamens ten, with a band of down near the base; ovary scaly; style glabrous; flower-stalk 1⁄2 in. long. (s. Carolinianum)
Native of the mountains of N. and S. Carolina and Tennessee. The true R. minus (punctatum) differs from R. carolinianum in the following particulars: its leaves are more pointed; its habit straggling and taller; the corolla-lobes are shorter than the tube and much more scaly outside (in R. carolinianum the corolla is only slightly or not at all scaly); corolla conspicuously spotted.
R. carolinianum is by far the best species in the series to which it gives its name, especially in the form with very pale rosy-pink flowers and deep red young stems. According to the American authority D. G. Leach ‘the less rusty the leaf undersurface, the lighter will usually be the color of the flowers and the later the plant will bloom’ (Rhododendrons of the World, p. 139). The leaves of the previous year usually colour brilliant red before falling in the autumn. A.M. May 20, 1968.
var. album Rehd. – Flowers white. There are two forms of this in cultivation. One is tall-growing with leaves more acuminately pointed than usual and with a yellowish blotch in the flowers. This is very vigorous and produced thickets of self-sown seedlings in peaty woodland. This may represent the wild form, said to be common in North Carolina along the Blue Ridge. The other cultivated form is much dwarfer and more compact and has flowers heavily spotted with green.
R. chapmanii A. Gray – This species, confined to the pinelands of the coast region of N. Florida, is closely allied to R. carolinianum. The leaves are distinct in their oval shape and rounded apex, 1 to 21⁄2 in. long, more than half as much wide. Flowers with a longer tube – 3⁄4 in. or slightly more long, the lobes sometimes crisped. Although hardy, it is in no way superior to R. carolinianum as a garden plant.