Publication: Sp. Pl. 1: 432. 1753 [1 May 1753]
Description
Sedum album or white stonecrop, is a succulent plant of the genus Sedum in the family Crassulaceae. It is a minutely puberulent, papillose, laxly tufted perennial herb that forms mat-like stands, typically growing to 10 cm tall with a spread to 25-30 cm wide. Much of the year the stems are short, semi prostrate and densely clad in leaves. Tiny, star-like, white flowers in clusters (cymes) bloom in mid-summer above the foliage mat. Flowers are attractive to butterflies. S. album is a very variable species, especially in the size and shape of the leaves and flowers. Although some segregate taxa seem sufficiently distinct to be given specific or subspecific rank, intermediate plants are so numerous as to make their diagnosis impossible.
Derivation of specific epithet. Specific epithet from Latin means white in obvious reference to the flowers.
Stems: Branching basally, succulent, but brittle, reddish in colour, densely glandular-pubescent, creeping and twisted with short ascending non-flowering shoots, not bearing rosettes. At the flowering time in July and August, the stems lengthen and are erect, occasionally branched and often pinkish-brown. Flowering branches erect, 5-18(-30) cm long.
Roots: Shallow and thin produced by stolons.
Leaves: Alternate, speading or appressed, sessile, fleshy and nearly cylindrical to ovoid-globose with a blunt, rounded tip, subterete but somewhat flattened on the upper face, glabrous or sparsely pubescent, green, not glaucous, but sometimes tinged with pink, especially in drought-stressed plants, 4-20(-25) mm long, 1?20 mm thick, and often turning reddish brown for autumn and winter.
Inflorescences: Many flowered rather dense paniculate-umbellate cymes (15?50+-flowered), 3?5-branched, bracteate, branches reflexed, forked. Bracts 1 per flower, similar to leaves, smaller. Pedicels 3?5 mm long.
Flowers: The calyx has five, ovate to triangular, fleshy sepals erect, and fused at the base 1-2 mm long. The corolla is regular (actinomorphic), approx. 0.5?1 cm broad and consists of five regular, spreading, lanceolate, petals 2-4.5 mm long, not fused at base, white or rarely pink and round-tipped. There are ten stamens, a separate gynoecium and five pistils. Filaments white. Anthers red. Nectar scales, white or yellow, spatulate. Styles slender, to 1 mm long.
Blooming season: Flowering summer?autumn.
Fruits: The fruit is five united, many-seeded erect, whitish follicles.
Seeds: Oblong or ovoid, pale, yellowish-brown, ribbed.
Chromosome number: 2n = 34, 51, 68, 85, 102. 136.
Origin and Habitat
Sedum album is found in the northern temperate regions of Europe (except for parts of the North and and East). Mediterranean and Northern Africa. It was recently also recorded from Western Asia, Iran, and Siberia and this constitutes a considerable range extension. S. album has been introduced and is naturalized in the United States (California, Indiana, Maine, Michigan,Ohio, New york, Oregon, Utah, Washington Wyoming) and in Canada (Ontario, Quebec, and British Columbia)
Altitude range: 60–1400 metres above sea level.
Habitat and ecology: Sedum album is a low-growing plant that cannot compete with more vigorous fast-growing species. It is specially adapted for growing in crevices or thin dry free-draining rocky soil and can be found on walls, dry banks, seashore rocks and in rocky meadows.
Cultivation and Propagation
Sedum album is a succulent perennial sedum, with white flowers as the species name suggests. It is a small but extremely tough plant that is best when planted in groups or massed as a ground cover. May be grown in rock gardens or border fronts. Best used in areas where unusual foliage texture and colour are appreciated. The leaves grow close together and form a dense carpet of plant material which spreads to cover a good-sized area. As a long-day plant it grows vegetatively for most of the year and dainty, airy white flowers bloom in midsummer. Foliage persists throughout the winter months, but turns red to bronze as temperatures become cooler. S. album can tolerate sun, shade, and dry soils, but looks its best only when given adequate light levels and water, and ideally should be grown outdoors in full sun. Not only heat resistant and drought tolerant, it is reliably hardy and provides interest year round, and needs only minimal care to reward you with its attractive texture. A continually successful plant on green roofs, Sedum album has become a staple plant in the industry. Be aware when planting that the amount of sun and water this plant receives also affects the color of the foliage.
Exposure: It prefers light shade with ample airflow rather than full sun, except in cool coast-side locations. Bright light is required to prevent “stretching” of Sedums (“stretching” occurs when a moderately fast growing plant such as an Sedum, is grown in dim light or over-fertilized, which causes overly lush growth that contributes to weak, pallid plants).
Waterings: Sedums are able to tolerate extended dry periods and survive drought without the need for watering, but they will grow stronger if they receive adequate moisture during their growing season, but never allowing the plant to remain waterlogged (root rot sensitive). Avoid overhead watering under humid conditions, especially during winter.
Soil: It is essential in cultivation to use a very porous soil, which will allow quick drainage. Sedums are shallow rooted plants, and therefore benefit from good levels of organic matter in the soil. Give it enough root space for optimum growth.
Ventilation: Good air movement is important for minimising pest and disease risks, and avoiding excessive humidity in cool winter conditions is important to successfully growing Sedums in the nursery environment.
Hardiness: Cold-hardy, it can take overnight temperatures to -25 C however, the ideal temperature range during the summer growing season is 5-25°C, with the cooler autumn temperatures tending to make their foliage colours become more intense than those of the active summer growing season.
Pests and diseases:* Aphids like this plant (and all flowering sedums).
Bibliography
Major references and further lectures
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Urs Eggli “Illustrated Handbook of Succulent Plants: Crassulaceae” Springer Science & Business Media, 06 December 2012
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Hideaki Ohba “Flora of North America”, Vol 8, http://plants.jstor.org/stable/10.5555/al.ap.flora.fna008000433?searchUri=filter%3Dname%26so%3Dps\_group\_by\_genus\_species%2Basc%26Query%3DSedum%2Balbum
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Wikipedia contributors. “Sedum album.” Wikipedia, The Free Encyclopedia. Wikipedia, The Free Encyclopedia, 4 Mar. 2016. Web. 12 Feb. 2017.
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Sedum album. (2016, 30 de octubre). Wikipedia, La enciclopedia libre. Fecha de consulta: 11:29, febrero 12, 2017 desde https://es.wikipedia.org/w/index.php?title=Sedum\_album&oldid=94678196.
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Tela Botanica. Sedum album http://www.tela-botanica.org/bdtfx-nn-62141-synthese
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Missouri Botanical Garden: Sedum album subsp. teretifolium ‘Murale’ Web. 12 Feb. 2017. http://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?kempercode=b885
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“White stonecrop: Sedum album”. NatureGate. Web. 12 Feb. 2017. http://www.luontoportti.com/suomi/en/kukkakasvit/white-stonecrop
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Clausen, R. T. “Sedum of North America North of the Mexican plateau”. 1975.
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Voss, E. G. “Michigan Flora. Part II Dicots (Saururaceae-Cornaceae).” Bull. Cranbrook Inst. Sci. 59. xix + 724.1985.
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Maria Teresa della Beffa, “Fiori di campo”, Novara, Istituto Geografico De Agostini, 2002.
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Giacomo Nicolini, “Enciclopedia Botanica Motta”. Volume terzo, Milano, Federico Motta Editore, 1960
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Sandro Pignatti, “Flora d’Italia”. Volume primo, Bologna, Edagricole, 1982