A robust shrub 10 to 20 ft high, as much or more in diameter; young shoots glabrous, green; the year-old shoots grey, not peeling. Leaves of the barren shoots oval or ovate, broadly tapered or rounded at the base, pointed, sparsely and irregularly toothed, 2 to 5 in. long, about half as wide, dull and almost glabrous above, downy beneath; with three or five prominent veins. Leaves of the flowering twigs smaller. Flowers pure white, 13⁄4 in. wide, not much scented; produced in June at the end, and in the uppermost leaf-axils of lateral twigs, usually seven or nine each. Calyx-lobes 2⁄5 in. long, lanceolate, and, like the individual flower-stalks, downy.
Native of the S.E. United States; introduced early last century. It is a fine free-flowering shrub, not uncommon in gardens, distinguished chiefly by the year-old bark not peeling, the numerous flowers in each raceme, and the downy calyx. One of the finest and noblest of mock oranges.
P. intectus Beadle P. pubescens var. intectus (Beadle) A. H. Moore; P. latifolius verrucosus Hort. – This philadelphus resembles P. pubescens in size, bark, foliage, and inflorescence, and is usually considered to be a variety of it, differing in the glabrous leaf-undersides, pedicels, and calyx-tube, but Dr Hu considers it to be a distinct species, more closely allied to P. lewisii than to P. pubescens. It is reported from Kentucky, Tennessee, and Oklahoma. Some of the tall-growing mock oranges found in older gardens may belong here rather than to P. pubescens.
P. × nivalis Jacques P. verrucosus Hort., not Schrad. – A hybrid of P. pubescens, differing from it chiefly in the peeling second-year bark. The other parent is thought to be P. coronarius, from which it differs in having the leaves sparsely toothed or almost entire, as in P. pubescens and in the usually hairy calyx. Such plants have been in cultivation since the middle of the last century and were grown as P. verrucosus and perhaps under other names. In P. × nivalis ‘Plenus’ the flowers are double.