Probably a chance hybrid of R. wiltonii (Subsect. Taliensia). It was raised at Edinburgh from seed as Wilson 1353, herbarium specimens of which are referrable to R. wiltonii. Royal Horticultural Society (1997)
A dense evergreen shrub up to 8 ft high; young branchlets densely white-scurfy; terminal leaf-buds elongate, their outer scales woolly, awl-shaped, with curved tips, much longer than the inner scales. Leaves oblong, 2 to 5 in. long, 11⁄4 to 2 in. wide, obtuse to rounded and abruptly mucronate at the apex, rounded to obtuse at the base, upper surface rugulose, glabrous, lower pale green with a patchy and scurfy grey or brown indumentum, midrib and lateral veins prominent; petiole about 1 in. long. Flowers about eight in a cluster, opening in April or May; pedicels about 1 in. long, hairy. Calyx minute, hairy. Corolla five-lobed, campanulate, about 13⁄4 in. long, white with lines of crimson speckles uniting at the base into a crimson blotch. Stamens ten, with dark anthers, filaments downy at the base. Ovary cylindric, densely hairy; style glabrous. (s. Taliense ss. Wasonii)
R. paradoxum was described in 1922 from a plant raised from Wilson’s 1353, collected during his first expedition for the Arnold Arboretum. But the herbarium specimen under that number is R. wiltonii, and so too were many of the plants raised from this batch of seed. R. paradoxum is certainly distinct from R. wiltonil, which has a much thicker indumentum and differently shaped leaves, but might be a hybrid of it.
Probably a natural hybrid of R. wiltonii (Rev. 2, p. 431).
R. inopinum – Probably a natural hybrid of R. wasonii (Rev. 2, l.c.).