Dahlia
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| Dahlia | ||||||||||||
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30 species, 20,000 cultivars |
Dahlia is a genus of bushy, summer- and autumn-flowering, tuberous perennials that are originally from Mexico, where they are the national flower.
In 1872 a box of Dahlia roots were sent from Mexico to the Netherlands. Only one plant survived the trip but produced spectacular red flowers with pointed petals. Nurserymen bred from this plant, which was named Dahlia juarezii with parents of Dahlias discovered earlier and these are the progenitors of all modern Dahlia hybrids. Ever since, plant breeders have been actively breeding Dahlias to produce hundreds of cultivars, usually chosen for their stunning and brightly colored flowers.
The Dahlia is a genus of bushy, tuberous, herbaceous perennial plants native to Mexico and Central America. A family of dicotyledonous plants, it is related to the sunflower, daisy, chrysanthemum, and zinnia. There are 42 species of dahlia, with hybrids commonly grown as garden plants. Flower forms are variable, with one head per stem; these can be as small as 5 cm (2 in) diameter or up to 30 cm (1 ft) ("dinner plate"). This great variety results from dahlias being octoploids—that is, they have eight sets of homologous chromosomes, whereas most plants have only two. In addition, dahlias also contain many transposons—genetic pieces that move from place to place upon an allele—which contributes to their manifesting such great diversity.
The stems are leafy, and most species do not produce scented flowers. Like most plants that do not attract pollinating insects through scent, they are brightly colored, displaying most hues, with the exception of blue.
The dahlia was declared the national flower of Mexico in 1963.[4] The tubers were grown as a food crop by the Aztecs, but this use largely died out after the Spanish Conquest. The dahlia is named after Swedish 18th-century botanist Anders Dahl.