S. HYPERICIFOLIA (_syn S. flagellata_).--Asia Minor, 1640. A wiry twiggy shrub, fully 4 feet high, with entire leaves, and small, white flowers produced in umbels at the tips of the last year's shoots. It is a pretty and desirable species.
S. JAPONICA (_syns S. callosa_ and _S. Fortunei_).--Japanese Spiraea. China and Japan, 1859. This is a robust species about a yard high, with large lanceolate leaves, and small, rosy-red flowers arranged in corymbose heads. Flowering at mid-summer. There are several fine varieties of this species, including S. japonica alba, a compact bush about a foot high with white flowers; S. japonica rubra differs from the type in having dark red flowers; S. japonica splendens, is a free-flowering dwarf plant, with peach-coloured flowers and suitable for forcing; and S. japonica superba, has dark rose-red flowers. S. Bumalda is a closely allied form, if not a mere variety of S. japonica. It is of dwarf habit, with dark reddish-purple flowers.
S. LAEVIGATA (_syns S. altaicensis_ and _S. altaica_).--Smooth Spiraea. Siberia, 1774. A stout, spreading shrub about a yard high, with large, oblong-lanceolate, smooth, and stalkless leaves. The white flowers are arranged in racemose panicles, and produced in May.
S. LINDLEYANA.--Lindley's Spiraea. Himalayas. A handsome, tall-growing species, growing from 6 feet to 8 feet high, with very large pinnate leaves, and pretty white flowers in large terminal panicles. It is the largest-leaved Spiraea in cultivation, and forms a stately, handsome specimen, and produces its showy flowers in great quantities. Flowering at the end of summer.
S. MEDIA (_syns S. confusa_ and _S. oblongifolia_).--Northern Asia, etc. The pure white flowers of this species are very freely produced in corymbs along the shoots of the previous season during the months of June and July. The lanceolate-elliptic leaves are serrate, or the smaller ones toothed near the apex only. Within the past few years the species has been brought into prominence for forcing purposes, for which it is admirably suited. It forms an upright, branching bush usually about 3 ft. high, and is best known under the name of S. confusa.
S. PRUNIFOLIA.--China and Japan, 1845. A twiggy-branched shrub growing 4 feet or 5 feet high, with oval, Plum-like leaves, and white flowers. There is a double-flowering variety named S. prunifolia flore-pleno, which is both distinct and beautiful.