Therorhodion camtschaticum (Pall.) Small

A deciduous shrub growing in low dense tufts 4 to 10 in. high, producing its flowers on stems up to 6 in. high. It spreads by means of underground suckers. Young shoots furnished with scattered bristles. Leaves stalkless, obovate, 3⁄4 to 2 in. long, 1⁄3 to 3⁄4 in. wide, thin in texture, glabrous above, slightly bristly beneath, and conspicuously so on the margin. Flowers solitary or in pairs (rarely in threes) on an erect, slender, glandular-bristly stem, the lateral flower or flowers produced on stalks 3⁄4 to 11⁄2 in. long; corolla 11⁄2 to 13⁄4 in. across, rosy crimson, with five open, spreading, oblong lobes, the three upper ones spotted. Calyx green, 1 in. across, the lobes narrowly oblong, bristly; stamens ten, very downy at the bottom. Bot. Mag., t. 8210.

Native of Japan in Hokkaido (and of one locality in Honshu), thence north through Sakhalin and the Kuriles to the Aleutians and W. Alaska; also on the mainland of Russia from the Ussuri region to Kamchatka; introduced to Britain a few years before 1802. This remarkable and pretty species thrives and flowers well on the rock garden at Edinburgh, but is difficult to suit in southern England, where, for no obvious reason, it succeeds in one garden and fails in another. It needs a light, acid, humus-rich soil, but special mixtures are unlikely to help; it is unsuitable for gardens with poor air drainage, where the expanding flower-shoots may be killed by late frost. Beyond that, no useful advice can be given, except that it should not be coddled.