A shrub 6 ft high, with gracefully arching, glabrous brown stems. Leaves rhomboidal or obovate, sometimes distinctly three-lobed, more or less broadly tapering and entire at the base, coarsely toothed on the upper half; 3⁄4 to 13⁄4 in. long, 1⁄2 to 11⁄4 in. wide; dark green above, rather glaucous beneath, glabrous on both sides. Flowers white, 1⁄3 in. across, produced during June in umbel-like clusters 1 to 2 in. across; calyx-lobes erect.
A hybrid between S. trilobata and S. cantoniensis; raised by Billiard, a nurseryman at Fontenay-aux-Roses, near Paris, about 1862. At its best it is probably the finest of all the white-flowered spiraeas, except perhaps S. ‘Arguta’; in low-lying situations it is subject to injury by late spring frosts. In more elevated gardens, or where the plant is not forced into premature activity by unseasonable warmth, there is no more desirable shrub, for it is very hardy. Its stems, at first erect, afterwards arching outwards at the top, bear the extraordinarily profuse blossoms on the upper side of the branches. It is one of the spiraeas which should have the older wood thinned out after flowering to allow light and air to enter and help in the development of the younger growths. It is very valuable for forcing early into bloom for indoor decoration, and used to be exhibited in this state at the spring shows under the erroneous name of S. confusa, a synonym of S. media – a less vigorous shrub with longer stamens and the calyx-lobes ultimately reflexed.