Editing Dahlia (section)

== Description ==
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| image1 = Dahlia Blooming.jpg
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| image2 = Dahlia Blooming Bud.jpg
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| image3 = Dahlia Almost Bloomed (2).jpg
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| footer = '''''Complete Stages of the Dahlia Flower:''''' (start from 2nd row 1st pic clockwise) flower in full bloom, flowering bud, partially opened bud, closed bud, bud on the stem, the full dahlia plant; photos taken at the [[National Institute of Technology Agartala|NIT Agartala]], [[India]]
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Dahlias are perennial plants with tuberous roots. They are not frost hardy, and require protection from frost if grown in regions with cold winters. While some have herbaceous stems, others have stems which lignify in the absence of secondary tissue and resprout following winter dormancy, allowing further seasons of growth.<ref name=Saar/> As members of the family [[Asteraceae]], dahlias have composite flower heads called [[Pseudanthium|capitula]] that are composed of multiple [[floret]]s arranged in a central disc with surrounding petal-like rays. Each floret is a flower in its own right. The modern name Asteraceae comes from the type genus ''[[Aster (genus)|Aster]]'' and the [[Ancient Greek]] word for "star", referring to the appearance of a star with surrounding rays.

The stems are leafy, ranging in height from as low as {{convert|12|in|cm|abbr=off|order=flip}} to more than {{convert|6|-|8|ft|m|abbr=off|order=flip}}. Flower forms are variable, with one head per stem; these can be as small as {{convert|2|in|cm|abbr=on|0|order=flip}} in diameter or up to {{convert|1|ft|cm|abbr=on|order=flip}} ("dinner plate"). The majority of species do not produce scented flowers. Like most plants that do not attract [[pollination|pollinating]] insects through scent, they are brightly colored, displaying most hues, with the exception of blue.

The great variety in species results from garden dahlias being [[octoploid]]s, having eight sets of [[Sequence homology|homologous]] [[chromosome]]s. 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.