DAHLIA

Kingdom : Plantae

(unranked) : Angiosperms

(unranked) : Eudicots

(unranked) : Asterids

Order : Asterales

Family : Asteraceae

Subfamily : Asteroideae

Tribe : Coreopsideae[1]

Genus : Dahlia Cav.

F. Hernández visited Mexico in 1615 and noticed two spectacular varieties of dahlias, which he mentioned in his account of medicinal plants of New Spain, not published until 1651. The French botanist Nicolas-Joseph Thiéry de Menonville, sent to Mexico to steal the cochineal insect valued for its scarlet dye, noted the strangely beautiful flowers he had seen in his official report, published in 1787. Seeds sent from the botanical garden of Mexico City to Madrid

flowered for the first time in the botanical garden in October 1789, and were named Dahlia coccinea by Antonio José Cavanilles, the head of the Madrid Botanical Garden, in his Icones plantarum, 1791. A few seeds were secured by Lord Bute and sent to England, where they flowered but were lost.

The introduction of the dahlia to the florists of the N

etherlands was effected about the same time, when a box of dahlia roots was sent from Mexico to the Netherlands. Only one plant survived the trip, but produced spectacular red flowers with pointed petals. Nurserymen in Europe crossbred from this plant, which was named Dahlia juarezii, with parents of dahlias discovered earlier: these are the progenitors of all modern dahlia hybrids. The Jardin des plantes in Paris received dahlias in 1802, again from

Madrid. A second species, D. variabilis, was at last successfully grown in 1804 by the gardener at Holland House, Kensington, of Lady Holland, who sent the seeds from Madrid. An early breeder of dahlias was comte Léon-Charles LeLieur de Ville-sur-Arce, intendant of the château de Saint-Cloud, its glasshouses and gardens, who had four varieties to work with, and by 1806 had produced three double-flowered dahlias.

Since 1813, commercial plant breeders have been breeding dahlias to produce thousands of cultivars, usually chosen for their stunning and brightly coloured waxy flowers. Dahlia was named the national flower of Mexico in 1963. Dahlia plants range in height from as low as 12 in (30 cm) to as tall as 6–8 ft (1.8–2.4 m). The flowers can be as small as 2 in (5.1 cm) in diameter or up to 1 ft (30 cm) ("dinner plate"). The great variety results from dahlias being octoploids (they have eight sets of homologous chromosomes, whereas most plants have only two).