|Spiraea subsp. var.||Bridal wreath, Spirea|
- For the European and west Asian herb in the same family, see Meadowsweet.
Spiraea (pronounced /spaɪˈriː.ə/), or meadowsweet, is a genus of about 80-100 species of shrubs in the family Rosaceae, subfamily Spiraeoideae. They are native to the temperate Northern Hemisphere, with the greatest diversity in eastern Asia.
The genus was formerly treated as also containing the herbaceous species now segregated into the genera Filipendula and Aruncus; recent genetic evidence has shown that Filipendula is only distantly related to Spiraea, belonging in the subfamily Rosoideae.
|Standard Cyclopedia of Horticulture|
Spiraea (ancient Greek name of a plant used for garlands, derived from speira, band, wreath; probably first used for the present genus by Clusius). Rosaceae, subfam. Spiraeeae. Spirea. Ornamental woody plants grown for their profuse handsome white, pink, or carmine flowers.
Deciduous shrubs: lvs. simple, short-petioled, dentate or serrate, sometimes lobed, rarely entire, without stipules: fls. in umbel-like racemes, corymbs or panicles, perfect, rarely polygamous; calyx cup-shaped or campanulate, 5-lobed; petals 5, rounded; stamens 15-60, inserted between calyx and disk; pistils usually 5, distinct, developing into follicles dehiscent along the inner suture, with several minute oblong seeds.—About 70 species in the temperate regions of the northern hemisphere, in Amer. south to Mex., in Asia south to the Himalayas. Many species formerly included under Spiraea are now referred to other genera; see Physocarpus, Holodiscus, Sorbaria, also Chamaebatiaria, Luetkea, Petrophytum, and Sibiraea for shrubby species, and Aruncus, Filipendula, and also Astilbe for the herbaceous ones. There is a monograph of Spiraea and the allied genera by Maximowicz in Acta Horti Petropolitani, vol. 6, pp. 105-261 (1879) and a monograph of the cult. species, with their numerous hybrids fully described by H. Zabel, Die strauchigen Spiraen der deutschen Garten (1893). There is much horticultural literature on spireas, for the plants are popular and about two-thirds of the known species and numerous hybrids mostly originated in gardens are in cult.
The spireas are very ornamental, usually low or medium-sized shrubs with rather small deciduous foliage and with small white or pink or sometimes nearly crimson flowers in showy corymbs or panicles followed by small inconspicuous capsule-like fruits. Many are hardy North; some of the best of them are S. arguta, S. Thunbergii, S. Vanhouttei, S. pubescens, S. trilobata, S. nipponica, S. media, S. ulmifolia, S. alba, S. Douglasii, S. Menziesii, S. tomentosa. The recently introduced S. Henryi, S. Veitchii, S. Wilsonii, S. Rosthornii and S. Sargentiana have proved hardy at the Arnold Arboretum, while S. blanda, S. japonica, and S. albiflora require a sheltered position or protection during the winter, though S. japonica and its allies, even if killed almost to the ground, will produce flowers on shoots of the same season. S. cantoniensis, S. Blumei, S. chinensis, S. canescens, and S. bella are more tender and not to be recommended for the North, but are hardy or nearly hardy in the middle states. S. prunifolia is hardy as far north as Boston.
In regard to the flowering season, the spireas can be divided into two groups. The first one contains the species of the section Chamaedryon, with white flowers in umbels and blooming in spring, from April to June. The second group is composed of the sections Calospira and Spiraria, with white or pink flowers in corymbs or panicles appearing from June to autumn. Some of the most important species, arranged according to their relative flowering-time, are the following: Early-flowering spireas—S. Thunbergii, S. arguta, S. hypericifolia, S. prunifolia, S. media, S. pikowiensis, S. pubescens, S. chamaedryfolia, S. trilobata, S. Vanhouttei, S. cantoniensis, S. nipponica. Late-flowering spireas—S. bella, S. Rosthornii, S. Wilsonii, S. Henryi, S. Sargentiana, S. Veitchii, S. corymbosa, S. densiflora, S. canescens, S. japonica, S. albiflora, S. salicifolia, S. alba, S. Menziesii, S. Douglasii, S. tomentosa. Many species of the second group do not produce their flowers all at once like those of the first group, but continue blooming for a longer time.
The spireas are all medium-sized or low shrubs and well adapted for borders of shrubberies, as single specimens on the lawn, or for rockeries. Especially the species of the early-flowering group possess a graceful habit and make effective single specimens, except perhaps S. chamaedryfolia and S. media, which are somewhat stiffer and less handsome and produce suckers. S. canescens, S. Henryi, and its allies have the graceful habit of the first group. S. japonica and its numerous hybrids form mostly low, round bushes and are pretty as single specimens or in the border. S. alba, S. Douglasii, S. Menziesii, and their hybrids should be planted in shrubberies only and especially in situations where their spreading by suckers does no harm; they are sometimes used for low ornamental hedges. For rockeries S. decumbens, S. betulifolia, S. corymbosa, S. densiflora, S. bullata, and some dwarf hybrids of S. japonica are to be recommended.
The species of the section Chamaedryon, and also S. canescens and S. bella, should be pruned as little as possible—only thinned out and the weak wood removed— while those of the sections Spiraria and Calospira can be pruned more severely if necessary, since they produce their flowers at the ends of the young shoots. Some of the early-flowering spireas, especially S. arguta, S. prunifolia, S. Vanhouttei, and S. Bumalda, are sometimes forced.
The spireas grow in almost any moderately moist soil and do not stand drought well, the spiraria species being generally more moisture-loving; S. tomentosa thrives well only in a peaty or sandy soil, while those recommended above for rockeries require a well-drained soil and sunny situation. Propagation is by seeds sown in spring and covered only slightly with soil, or by hardwood or greenwood cuttings. The species of Chamaedryon grow very well from greenwood cuttings under glass, while the spirarias are usually raised from hardwood cuttings. The calospiras seem to grow equally well in both ways. The spirarias are also often propagated by division and by suckers. CH
Pests and diseases
|Standard Cyclopedia of Horticulture|
S. Aitchisonii, Hemsl. – Sorbaria Aitchisonii.—S. amurensis, Maxim. –Physocarpus amurensis.—S. ariaefolia, Smith –Holodiscus discolor var. ariaefolius.—S. Aruncus, Linn.-Aruncus sylvester.—S. assimilis, Zabel (S. densiflora x S. japonica). Low shrub, with pink fls. in broad corymb-like panicles. Garden hybrid. —S. astilboides, Moore –Astilbe astilboides.—S. Boursieri, Carr.- Holodiscus Boursieri.—S. brumalis, Lange (probably S. expansa X S. alba). Medium-sized shrub, with oblong, incisely serrate, almost glabrous lvs. and pinkish white fls. in broad and loose corymb-like panicles. Aug.-Oct. Garden hybrid.—S. caespitosa, Nutt.-Petrophytum caespitosum.—S. calcicola, W. W. Smith. Shrub to 5 ft., with slender arching branches: lvs. small, obovate or elliptic, entire, glabrous: fls. white, pink outside, in 6-8-fld. umbels. S. W. China.—S. camtschatica, Pall.-Filipendula camtschatica.—S. capitata, Pursh-Physocarpus capitatus.—S. cinerea, Zabel (S. cana X S. hypericifolia). Medium-sized shrub, with small, oblong, usually entire, pubescent lvs. and white fls. in short-stalked umbels. Garden hybrid.—S. concinna, Zabel (S. albiflora x S. expansa). Medium-sized shrub, with lanceolate, sharply serrate, almost glabrous lvs. and pinkish white fls. in broad corymbs. Garden hybrid.—S. compacta multiflora, Hort.-Astilbe japonica var.—S. conferta, Zabel (S. cana x S. crenata). Medium-sized shrub, with small, ovate to oblong- lanceolate, 3-nerved, entire or crenate lvs. and white fls. in dense, small, peduncled umbels. Garden hybrid. —S. dahurica, Maxim., is closely allied to S. alpine, but not yet intro. S. canescens and Sorbaria sorbifolia are sometimes cult. under this name.—S. dasyantha, Bunge. Allied to S. chinensis. Lvs. ovate, cuneate at the base, incisely serrate or lobed, with grayish white tomentum beneath: infl. grayish tomentose; stamens half as long as petals. N. China.—S. Davidii, Hort.-Astilbe Davidii.—S. difformis, Zabel (S. alba x S. corymbosa). Medium-sized shrub, with oval to oblong-lanceolate, serrate, almost glabrous lvs. and white fls. in large corymb-like panicles. Garden hybrid.—S. digitata, Willd. –Filipendula palmata.—S. discolor, Pursh - Holodiscus discolor.—S. dumosa, Nutt. –Holodiscus dumosus.—S. Filipendula, Linn.-Filipendula hexapetala.—S. fissa, Lindl.-Holodiscus fissus.—S. floribunda. A trade name of indiscriminate meaning. S. semperflorens and Sorbaria sorbifolia are sometimes met with under this name.— S. gemmata, Zabel (S. mongolica, Hort., not Maxim.). Allied to S. alpina: axillary buds much longer than petioles: lvs. small, penninerved, oblong-lanceolate, usually entire: fls. white, in short-stalked, rather few-fld. umbels. Mongolia.—S. Gieseleriana, Zabel (S. cana x S. chamaedryfolia). Medium-sized shrub, with ovate, sharply serrate lvs. and rather large white fls. in long-stalked umbels. Garden hybrid.—S. gigantea, Hort.-Filipendula camtschatica.—S. gracilis, Maxim. (S. vacciniifolia, Lodd,. not Don). Low shrub, allied to S. canescens, with slender, arching branches: lvs. small, ovate, obtuse, entire or crenate above the middle, quite glabrous: fls. white, in hemispherical loose corymbs. Himalayas. L.B.C. 15: 1403. — S. grandiflora, Sweet - Sorbaria grandiflora. — S. grandiflora, Hook.- Exochorda racemosa. — S. Hacquetii, Fenzl & Koch. Closely allied to S. decumbens, but grayish-pubescent and with the sepals upright or spreading in fr. N. Italy, Tyrol. — S. Hookeri, garden name, applied to S. nudiflora, S. bella, S. expansa, S. tristis, and others, and also to Exochorda racemosa. — S. Humboldtii, Hort.-Aruncus sylvester. — S. inflexa, Koch (S. crenata X S. mollis). Medium-sized shrub, with slender arching branches: lvs. elliptic-oblong, entire, sparingly pubescent beneath: fls. white, rather large, in many-fld. stalked umbels. Garden hybrid. —S. japonica, Hort., not Linn. F.-Astilbe japonica. — S. kamaonensis spicata, Hort., is a form of S. semperflorens. — S. kamschatica, Auth.-Filipendula camtschatica. — S. laevigata, Linn.-Sibiraea laevigata. —S. laxiflora, Lindl. – S. vacciniifolia. —S. Lindleyana, Wall.-Sorbaria Lindleyana.—S. lobata, Gronov.-Filipendula rubra.—S. micropetala, Zabel (S. hypericifolia x S. media). Medium-sized shrub, with grayish green, oblong-obovate lvs., entire or serrate at the apex, 3- or penninerved: fls. white or greenish white, in umbels on leafy or naked stalks. —Garden hybrid. — S. Millefolium, Torr.- Chamaebatiaria Millefolium. — S. Miyabei, Koidzumi. Allied to S. bella and S. japonica. Lvs. ovate, incisely serrate, glabrous, 1 1/2 – 2 1/2 in. long: infl. 1 1/2 – 2 in. long-puberulous: fls. white, perfect; stamens much longer than petals: follicles upright, style spreading. Japan. Var. glabrata, Rehd. Lvs. broadly cuneate at base: infl. glabrous. Cent. China. Var. pilosula, Rehd. Lvs. pubescent on the veins beneath: infl. sparingly pilose. Cent. China. This species is very similar to S. chamaedryfolia in habit and foliage and also in the individual fls. but is easily distinguished by the compound corymb. Hardy at the Arnold Arboretum. —S. mollifolia, Rehd. Allied to S. alpina and S. cana. Spreading shrub, to 6 ft.: winter buds acuminate, 2-valved, longer than petioles: lvs. elliptic-oblong or oblong, entire or with few teeth at the apex, villous on both sides, 1/2 – 3/4 in. long: infl. villous:fls. 1/3 in. across, white: follicles upright, pubescent. W. China. —S. mollis, Koch (S. cana x S. media). Similar to S. media: lvs. smaller, usually entire, pubescent: fls. smaller, umbels pubescent. Garden origin. — S. mongolica, Maxim., is closely allied to S. crenata, but not yet intro.; the S. mongolica of gardens is S. gemmata. — S. monogyna, Torr. & Gray -Physocarpus monogynus. — S. myrtilloides, Rehd. Allied to S. alpina. Shrub, to 8 ft.: lvs. oval to obovate-oblong, entire, obtuse, rarely acutish, cuneate at the base, slightly pubescent beneath, 1/3 – 1/2 in. long: infl. dense, hemispherical, on short leafy branchlets: fls. White, 1/4 in. across: follicles upright, glabrous. W. China. Very graceful shrub. — S. nepalensis, a garden name applied to several species, as S. micropetala, S. canescens, S. salicifolia. —S. nivea, Zabel (S. canescens x S. expansa). Similar to S. canescens in habit, corymbs larger and looser: lvs. coarsely doubly serrate, pubescent, 1-2 in. long: fls. white or pinkish white. Garden hybrid. —S. nudiflora, Zabel (S. bella X S. ulmifolia). Medium-sized shrub, with ovate, doubly serrate, almost glabrous lvs. and pinkish white fls. in hemispherical corymbs. Handsome, almost hardy shrub. Garden hybrid. — S. opulifolia, Linn.— Physocarpus opulifolius. — S. oxyodon, Zabel (S. chamaedryfolia X S. media). Similar to S. media, but branches angular: lvs. narrower, follicles with the styles terminal and spreading. Garden hybrid. — S. Pallasii, Don- Sorbaria grandiflora. —S. palmata, Pall.-Filipendula palmata. — S. palmata, Thunb.-Filipendula purpurea. —S. palmata, Linn.-Filipendula rubra. — S. parvifolia, Bertol. S. gracilis. — S. pectinata, Torr. & Gray - Luetkea pectinata. — S. revirescens, Zabel (S. expansa X S. japonica). Medium-sized shrub, with oblong, coarsely serrate lvs., pubescent on the veins beneath: fls. light to deep pink, in large corymbs; blooming in summer and usually again in fall. Garden hybrid. —S. ribifolia, Nutt.-Physocarpus capitatus, — S. rubra, Zabel (S. ruberrima, Dipp. S. Douglasii x S. expansa). Upright medium-sized shrub, with oblong-lanceolate, coarsely serrate lvs. tomentose beneath, and deep pink fls. in ovate panicles. Garden hybrid. — S. Schinabeckii, Zabel (S. chamaedryfolia X S. trilobata). Medium-sized shrub, with arching branches: lvs. ovate to oblong-ovate, doubly serrate, glabrous: fls. white, rather large, in peduncled umbels; petals longer than stamens. Handsome shrub, similar to S. Vanhouttei. Garden hybrid. — S. sorbifolia, Linn.- Sorbaria sorbifolia. — S. Tobolskia, Lodd.- Sorbaria sorbifolia. — S. trifoliata, Linn.-Gillenia trifoliata. — S. tristis, Zabel. Hybrid of unknown origin, similar to S. expansa, but corymbs and the whitish pink fls. smaller; sepals upright in fr. — S. Ulmaria, Linn.-Filipendula Ulmaria. —S. vaccinifolia, D. Don (S. laxiflora, Lindl.). Shrub, to 2 ft., with arching branches: lvs. long-petioled, ovate, crenuately dentate, almost glabrous, 3/4 – 1 1/2 in. long: fls. Whitish, in tomentose corymbs, 1-3 in. across. June, July. Himalayas. F.S. 7, p. 190. — S. vaccinifolia, Lodd.-S. gracilis. — S. vaccinifolia, Hort. – S. canescens, S. brumalis. — S. venusta, Hort. – Filipendula rubra var. venusta. —S. venustula, Kunth & Bouche –S. vaccinifolia. CH
- Spiraea douglasii.jpg
Hardhack (Spiraea douglasii)
Japanese spiraea (Spiraea japonica)
Spiraea thunbergii flowers
- ↑ Sunset Western Garden Book, 1995:606–607