A robust evergreen shrub 6 to 10 ft high; young shoots downy. Leaves narrowly oblong, 4 or 5 in. long, 11⁄2 to 13⁄4 in. wide; with a short, abrupt tip and a rounded base; upper surface glabrous, the lower one more or less felted; stalk 1⁄2 to 3⁄4 in. long, very stout. Flowers creamy white, flushed with pink, or yellowish, up to twenty in a rounded cluster 4 to 6 in. across; rachis up to 11⁄4 in. long, lengthening in fruit; pedicels up to 11⁄4 in. long, downy. Calyx-lobes five, shallow. Corolla 2 in. across, broadly funnel-shaped, five-lobed, the lobes broad and rounded, emarginate, the three upper ones spotted with brownish or greenish yellow. Stamens ten, hairy at the base. Ovary covered with brown down; style glabrous. Bot. Mag., t. 7881.
Native of Japan at subalpine elevations, descending to near sea-level in Hokkaido; also of the Kuriles and, in the broad sense, of Korea; introduced to Britain towards the end of the last century. It is a very hardy shrub and for that reason valued in regions too cold for most of the species whose hardiness in the British Isles is taken for granted. It is at present placed in the Ponticum series, subseries Caucasicum – a very artificial grouping. Dr Cowan pointed out that the hairs composing its leaf-indumentum closely resemble those of the Lacteum series.
subsp. tigerstedtii Nitzelius – This Korean race is more robust than the Japanese, with stouter stems, larger leaves 6 to 10 in. long, 2 to 33⁄4 in. wide. The flowers are white, with greenish spotting, up to nearly 3 in. wide, the calyx is more developed and the fruit-stalks are longer (11⁄4 to 2 in. long, against 3⁄4 to 11⁄4 in. long in the Japanese plants). This subspecies was named by T. Nitzelius in honour of Mr Tigerstedt, who introduced it to his famous Mustila Arboretum in southern Finland from the Kongosan in central Korea (Deutsche Baumschule, July 1970, pp. 207-12). Plants in Britain raised from seeds collected by Wilson in Korea may belong here.