Cistus populifolius L.

An evergreen shrub 3 to 7 ft high, of vigorous growth; young shoots minutely downy and viscid. Leaves long-stalked, broadly ovate, with a deeply heart-shaped base, pointed; 1 to 31⁄2 in. long, 1 to 21⁄2 in. wide, prominently net-veined, ultimately glabrous; stalk 1⁄2 to 1 in. long, fringed with hairs. Flowers white, 2 in. across, with a yellow stain at the base of each petal, produced during June from the leaf-axils at the apex of the previous year’s growth and beneath the new growth, in two- to five-flowered clusters; flower-stalk hairy, 2 to 3 in. long. Sepals five, the outer ones heart-shaped, 3⁄4 in. long, 1⁄2 in. wide at the base; inner ones smaller.

Native of S.W. Europe; cultivated since 1656. It is quite distinct from all other cultivated species of rock rose in having leaves larger and longer-stalked than any. Whilst it will not withstand our hardest winters, it may still be included among the hardier species, and is well worth growing. The hardiest forms of this species are said to be those that grow in S.W. France around Narbonne. They have been given varietal status as var. narbonnensis Willk., said to differ in the shorter-stalked flower-clusters and the smaller sepals, hairy only on the margin, but Sir O. Warburg doubted whether these characters are constant enough to warrant a variety being made out of them [and they have indeed since been referred to the type subspecies (POWO 16/4/2025)].