An erect shrub, up to 6 ft high, the young shoots yellowish, glabrous, angular, zigzag. Leaves ovate or ovate-lanceolate, 11⁄2 to 3 in. long, 3⁄4 to 11⁄2 in. wide, coarsely, irregularly, often doubly toothed, dark green and glabrous above, somewhat glaucous and slightly downy beneath. Flowers 1⁄3 in. across, white, produced in a corymb or corymbose raceme 11⁄2 in. across; flower-stalks glabrous, slender, the lower ones 3⁄4 in. long, becoming shorter towards the summit. Stamens conspicuously long.
S. chamaedryfolia is a rather variable species with a wide natural distribution from the eastern Alps, Carpathians and Balkans eastward to Siberia and central Asia; farther east its place is taken by S. flexuosa and other closely related species.
var. ulmifolia (Scop.) Maxim. S. ulmifolia Scop. – Leaves ovate, the upper two-thirds coarsely toothed. The inflorescence is more of a raceme than a corymb, and from 11⁄2 to 2 in. long; flowers white, about 1⁄2 in. across in cultivated plants. This is the handsomest form of S. chamaedryfolia, distinct in its broader leaves and more elongated inflorescence. It was described from Europe and is said to be the predominant state of the species in the western part of its range.
S. chamaedryfolia is in all its variations an attractive and quite reliable shrub, usually escaping spring frosts and flowering in May (var. ulmifolia towards the end of the month). It renews itself by sending up every year strong, erect sucker-growths from the ground, which produce flowers on short twigs in the following year; and, to give these their best chance, sufficient of the old shoots should be pruned out after flowering to enable them to develop strongly and freely.
S. × nudiflora Zab. S. hookeri Hort. ex Zab. – A hybrid of S. chamaedryfolia var. ulmifolia and S. bella. Leaves almost glabrous, ovate, doubly toothed or incised, up to 21⁄2 in. long on strong shoots, to 11⁄2 in. on the flowering laterals, which are produced all along the previous year’s growths. Flowers rose-coloured, borne in racemose umbels which are sometimes supplemented by clusters from the axils of bracts or reduced leaves, the whole inflorescence then up to 3 in. wide. An interesting hybrid which unites sect. Chamaedryon with the Japonica group of sect. Calospira. It was distributed on the continent by the Berlin nurseryman Lorberg, who obtained it from England under the name ’S. hookeri’, already in use for some other hybrid, and also a horticultural synonym of S. bella. It was given further circulation in the 1890s by Messrs Hesse under the name given to it by Zabel.
S. × schinabeckii Zab. – A handsome hybrid between S. ch. var. ulmifolia and S. trilobata. It is a twiggy bush to about 6 ft high with white flowers in stalked umbels, at their best in June. Lower leaves on the shoots roundish, the upper ovate, doubly toothed, about 2 in. long. The flowers are larger than is usual in S. chamaedryfolia, longer than the stamens (shorter in the species).
S. flexuosa Fisch. S. ch. var. flexuosa (Fisch.) Maxim. – Closely related to S. chamaedryfolia and probably no more than a variety of it. It is distinguished by the more conspicuously angled (or winged) stems, the dwarfer habit, the smaller narrower leaves simply-toothed on the upper third or half only, sometimes almost entire, and by the flowers being fewer in the cluster. Native of Siberia.