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dahlia(däl`yə, dăl`–) [for Anders Dahl, 1751–89, Swedish botanist and pupil of LinnaeusLinnaeus, Carolus
, 1707–78, Swedish botanist and taxonomist, considered the founder of the binomial system of nomenclature and the originator of modern scientific classification of plants and animals. He studied botany and medicine and taught both at Uppsala.
..... Click the link for more information. ], any plant of the genus Dahlia of the family Asteraceae (asteraster
[Gr.,=star], common name for the Asteraceae (Compositae), the aster family, in North America, name for plants of the genus Aster, sometimes called wild asters, and for a related plant more correctly called China aster (Callistephus chinensis
..... Click the link for more information. family), tuberous-rooted perennials native to Mexico and Guatemala and widely cultivated in gardens. Most of the several thousand horticultural varieties have been developed from the single species (D. pinnata) of garden dahlia introduced into cultivation in England c.1800, but other species and hybrids, e.g., the cactus dahlia (D. juarezii) are also grown. Dahlias are stout and rather woody plants, some species reaching the stature of small trees, with late-blooming flowers in a wide range of colors and sizes. The tubers of the garden dahlia were one source of fructose, used by diabetics. Dahlias are classified in the division MagnoliophytaMagnoliophyta
, division of the plant kingdom consisting of those organisms commonly called the flowering plants, or angiosperms. The angiosperms have leaves, stems, and roots, and vascular, or conducting, tissue (xylem and phloem).
..... Click the link for more information. , class Magnoliopsida, order Asterales, family Asteraceae.
a genus of perennial herbaceous plants of the thistle family (Compositae), with thickened, tuberoid roots. The stalk is hollow, 35-200 cm high. The leaves are opposite, pinnate, or triple pinnate. The inflorescence is a calathide and consists of a large number of tubular and Ungulate blossoms, or only ungulate blossoms, extremely varied in color. Approximately 15 wild species are known, distributed in Mexico and Guatemala.
The dahlia appeared in cultivation in Europe at the end of the 18th century. There are more than 8,000 varieties, obtained by hybridization. Garden dahlias are divided into three groups, according to type of inflorescence: single (simple and miniature), with one row of outer Ungulate blossoms (the rest of the blossoms are tubular); semidouble (anemone-like and collar-shaped), with two to three rows of Ungulate blossoms; and double (pompoms, globular dahlias, ornamentals, cactus dahlias, and several others), in which the tubular blossoms are all or almost all transformed into Ungulate ones (barren ones). The dimensions of the inflorescences are 3-35 cm. In ornamental horticulture dahlias are used for individual and group plantings and as cut flowers.
Dahlias are propagated by cuttings, division of tubers, and seeds. Well-lighted areas with fertilized soils are used for dahlia plantings. In order to obtain large flowers, no more than three stems are left on the bush; superfluous shoots are removed as soon as they appear, as are side shoots (shoots in the leaf axils). Care consists of abundant irrigation, frequent cultivation of the soil, feeding, and weeding. Tubers are dug up after autumn frosts for winter storage. The dried tubers are stored in a dry, dark place at a temperature of 4°-5° C in a single layer.
REFERENCESSharonova, M. Georginy. Moscow, 1952.
Zalivskii, I. L. Georginy, 3rd ed. Moscow-Leningrad, 1959.