The genus Dahlia belongs to family Asteraceae. The so-called flower of Dahlia is a capitulum inflorescence made up of many flowers (florets) arranged peculiarly. The outer ray florets have all the flower colours (in which the male organs are modified into strap-shaped petals), whereas the inner disc florets are yellow.
A joint Dahlia committee formed by drawing an equal number of members from national Dahlia society and the Royal Horticultural Society in England has classified modern Dahlias into following main types.
(Note: In the following descriptions, the Dahlia inflorescence is referred as Flower/bloom & the ray florets are referred as petals for simplification purpose)
10 varieties of modern Dahlia flowers:
1. Single-flowered Dahlias:
Flowers in this group consist of a single set of petals around the central disc. The blooms are about 10 cm in diameter.
2. Star Dahlias:
The blooms are small, consisting of 2 or 3 rows of somewhat pointed petals which are slightly incurved forming a cup around the central disc.
3. Anemone-flowered Dahlias:
In this group, the flowers have a dense dome-shaped central disc of tubular florets surrounded by an outer ring of petals.
4. Collarette Dahlias:
The flowers of this group somewhat resemble the singles, but there is an additional ring of small petals (the collar), which are about half the length of outer petals. Buy flower seeds online in India.
5. Paeony flowered Dahlias:
This group consists of semi-double blooms of a few rows of petals surrounding a central disc. The blooms may be of large, medium or small size.
6. Decorative Dahlias:
The blooms of this class are fully double, and the central disc is not visible until the blooms are aged. The petals are flat and broad with a blunt point.
7. Cactus dahlias:
These also have fully double blooms like decorative Dahlias. Petals in this group are narrower and more pointed like cactus spines. Sometimes petals tend to curve backwards. Buy decorative flowering plants online.
8. Double show & fancy Dahlias:
The blooms in this group are also fully double, almost globular, with small central florets. The Margins of petals are incurved, tubular, and blunt at mouth. The flowers are over 10 cm in diameter.
9. Pompom Dahlias:
These resemble exactly the double show and fancy Dahlias in shape of bloom except that these are much smaller in size.
10. Dwarf bedding Dahlias:
The height of the plants in this group is between 30 and 60 cm which is much less than regular Dahlia plant, but the formation of the flower may belong to any of the above groups.
Apart from these, there are many small groups of Dahlias which are not covered by any one of the above classes. These are referred as miscellaneous Dahlias.
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