There are no active references in this article.
A shrub 4 to 6 ft high, with angular, slightly hairy young branches. Leaves thin, broadly ovate, pointed, doubly toothed towards the apex, 1 to 21⁄4 in. long on the barren shoots, shorter, relatively narrower, and simply toothed on the flowering ones, glabrous above, glaucous or whitish, and more or less downy beneath; stalks up to 1⁄4 in. long. Flowers unisexual, about 1⁄4 in. across, produced around midsummer in corymbs 3⁄4 to 11⁄2 in. across, at the ends of lateral shoots. Stamens longer than the petals (small and abortive in female flowers). Follicles glabrous except for down on the inner suture. Bot. Mag., t. 2426.
Native of the Himalaya from Kashmir eastward, extending into China; introduced from Nepal about 1820. In spite of its name this shrub is not one of the best of the spiraeas, but was widely grown in the last century until displaced by S. japonica. Even with the exclusion of S. amoena (see below) the species is variable. The branches may be erect or arching and the flower-bearing laterals vary considerable in length, as does the width of the inflorescence, which on some wild plants may be more than 11⁄2 in. across. S. bella is allied to S. japonica but differs most obviously in its dioeciousness and the shorter flowering branches.
S. amoena Spae S. expansa K. Koch; S. fastigiata Schneid.; S. bella sens. Hook. f., in part, not Sims – A shrub up to 6 ft high, with slender, round, downy stems, erect and not much branched; buds hairy. Leaves lanceolate to ovate up to 4 in. long by 11⁄4 in. wide, coarsely and sharply toothed (both simply and doubly) except at the base, dark green above, hairy on the veins and rather glaucous beneath; stalks 1⁄4 to 3⁄8 in. long. Flowers white with a flush of red, borne in flat compound corymbs from 2 to 8 in. across; calyx and flower-stalks downy. It blossoms on the shoots of the year in July and August.
Native of the Himalaya; in cultivation by the 1840s and perhaps introduced at the same time as S. bella. It is closely allied to that variable and little studied species and included in it by the younger Hooker as ‘the fastigiata form of S. bella’. The two are difficult to separate in the herbarium, but in cultivation they are really quite distinct and it is convenient to keep them apart nomenclaturally. S. amoena has white flowers in large flat corymbs borne in late summer on long terete branches and in general aspect bears a greater likeness to S. micrantha (see below) than to S. bella, with pink flowers on short or shortish laterals in smaller corymbs opening earlier in the season.
Plants now in commerce under the name “S. japonica fastigiata” (1978) appear to be S. amoena, though a singularly fine form of it, with a very large central corymb supplemented on strong shoots by clusters at the ends of axillary growths, opening later. The flowers are male, pink in the bud, opening white, with a conspicuous ring of disk-glands, which are purplish pink at first, later yellowish; abortive carpels pink. Distributed by the Sunningdale Nurseries, the stock came from a Cotswold garden whose owner had acquired the original plant from a Scandinavian nursery. It is therefore of interest that this clone agrees in every discernible detail with specimens of a spiraea cultivated in Denmark as S. expansa, which were collected by the botanist Lange in August 1869 and August 1881 and are now preserved in the Kew Herbarium. It also agrees with Lange’s description of S. expansa, obviously made from a cultivated plant, in Bot. Tidskr., Vol. 13 (1882), p. 28. The possibility that this spiraea is a hybrid has been considered, but seems unlikely.
note. It has been suggested that the name S. amoena Spae (1846) is illegitimate on the grounds that it is a later homonym of S. amena Raf. (1838). This would indeed be the case if ‘amena’ is to be regarded as an orthographic variant of ‘amoena’. But Rafinesque did not explain his choice of epithet, which he may have taken from the Greek ‘amenes’, meaning weak. If the name S. amoena had to be discarded, the correct name for the species, if kept separate from S. bella, would be S. expansa K. Koch, not S. fastigiata Schneid., the name used by Rehder in the Bibliography.
S. micrantha Hook. f. S. japonica var. himalaica Kitamura – This comes near to S. amoena but the leaves are usually thinner, more acuminate at the apex, the flowers are mostly hermaphrodite, the inflorescence is more open, with woollier branches, and the follicles are densely hairy. It is also closely allied to S. japonica, but the densely indumented inflorescence, white or pale pink flowers and hairy follicles distinguish it. Native of the Himalaya from Nepal eastward, and of N.E. India. It was cultivated at Kew in the last century from seeds collected by J. D. Hooker in Sikkim but the plants now at Kew and in other collections were raised from B.L. & M. 292, collected by the University of North Wales Expedition to E. Nepal in 1971.