Consider the varieties and classifications of dahlia varieties used in culture.
Currently, botanical species of dahlias, which are about 30, are not used in culture, giving way to numerous varieties obtained by long-term crossing of Mexican species D. Coccinea and D. variabilis. The hybrids are combined into one species, called the “cultivated or variable dahlia (Dahlia cultorum Thorsr. et Reis.). The number of varieties created is about 15,000, so it became necessary to classify them according to various characteristics.
By height, flowerbeds, 30-60 cm high, and border dahlias are distinguished. Curb, in turn, are divided into tall, over 1.2 m high, medium-sized, 0.9 – 1.2 m, and undersized dahlias, 60-90 cm in height.
According to the size of the flower, plants are divided into giant, with an inflorescence size of over 25 cm, large – 20-25 cm, medium – 15-20, small – 10-15 cm, and miniature, with inflorescences not exceeding 10 cm in size.
The main, and most difficult classification is according to the degree of doubleness, shape and structure of the flower. The huge variety of varieties brought to life the need to develop a unified international system of such a classification that could replace national ones, which was done in 1962 in Brussels. According to the international classification, all varieties are divided into 10 groups or classes:
Non-double, or simple, in which oval-shaped reed flowers are arranged in 1-3 rows around a flat disc of small tubular ones, a subclass is single-row minions, with a height of 35-40 cm and an inflorescence diameter of less than 5 cm.
Anemone , with inflorescences of 1-3 rows of flat petals arranged around large tubular flowers forming a convex center.
Collared , distinguished by the presence of two circles of reed flowers, the oval petals of the outer circle are much longer, deployed around standing, slightly twisted and usually differently colored inner petals, covering the center of tubular flowers like a collar.
Peony , have semi-double inflorescences of two or more rows of oval large petals around a small yellow central disc.
Decorative , with double inflorescences of wide, flat or wavy reed flowers, usually covering the tubular center; one of the subclasses, sometimes separated into a separate group, nymphaeals, in appearance resemble a lotus flower or water lilies, have wide, slightly concave oval flowers arranged in closed circles.
Spherical , with petals rounded at the ends, folded into a funnel-shaped tube up to half the length, forming double spherical or hemispherical inflorescences.
Pompoms , having spherical inflorescences much smaller than those of the previous group, up to 7 cm in diameter, the petals are folded into a tube along the entire length.
Cactus , with flowers straight or curved at the ends, rolled into a tube by more than half, formed into double inflorescences, subclass – chrysanthemum-shaped, having narrow marginal petals, long and rolled into a tube at the end.
Semi- cactus , a transitional form between cactus and decorative, differs from the previous group in wider petals at the base, sharp at the ends, twisted into a tube half or less.
Mixed or transitional , include varieties that are not included in the other groups.
Soviet breeders used a different classification and divided plants into two groups, double and non-double.
Non -double, in turn, were divided into non-double or simple (subclass – undersized minions) , collared , pion -shaped and anemic .
The terry group included decorative , spherical , pompom , cactus , semi – cactus and mixed .
In addition to the perennial dahlia variable, mostly grown by planting tubers, another species is used in floriculture, the annual pinnata dahlia (D. pinnata Caw.), A plant 35-60 cm high, blooming in June with simple, 6 cm in diameter, various colors inflorescences. This species, propagated by seeds through seedlings, looks very impressive in flowerbeds, flowerbeds and balconies.
Popular varieties of dahlias
In modern floriculture, there is a huge number of hybrid dahlias, differing in size, shades, size and shape of flowers. Consider some popular varieties, for convenience, placing them in groups in accordance with the international classification.
Single-row dahlias are represented by the well-known Merry Fellows, annual dahlias, planted by seeds and blooming in June. They also include varieties:
Red Rote Funken.
Pink with a yellow center Lady Eileen.
Pale red with pink tips Horhofen .
Yellow Yellow Hammer.
Red Murillo and Preston Park.
Minion Topmix White.
The anemic ones include the lilac and yellow variety Lucy, as well as undersized ones:
Bronze Vera Higgins.
White with yellow Lemon Puff.
The following varieties of dahlias of the collar group are recommended for cultivation:
Red with white “collar” Gerlings Elite.
White with dark red Goth Yasu.
Undersized maroon with yellow Chimborazo.
Yellow Claire de Lune.
Purple and white La Cierva.
Peony-shaped dahlias are now rarely used in culture, however, there are a number of interesting varieties , for example, double red Eternal Flame, Danko, densely double fiery red Aurora Volley, foreign selection:
Among decorative dahlias there are both tall:
Dark red Arabian Night.
Salmon with yellow Extase.
Varieties with giant flowers:
Yellow Kelvin Floodlight.
A subclass of nymphs, a variety of decorative ones, is represented by pale pink Gerry Hawk and Pink Tiara, white Jeanette, etc.
The globular group includes a large number of giants, the best of which are Edinburgh, purple with white tips, Yuri Gagarin, dark red, lemon Youwell, as well as miniature Candy Cupid, pale pink, Wootton Cupid, pink.
Popular pom-pom varieties:
Light pink Gretchen Heine.
Yellow with rowan tips Krokha.
Fatima (dark pink color).
Ancress is white with lilac tips.
White Small World.
Red Willo’s Surprise, etc.
Among the cacti there are giants with large inflorescences Prefight Demanche, pink-crimson 130 mm high, pink Danny, a number of small plants, for example, pink Athalie, red Doris Day, golden ‘Border Princess’.
The semi-cactus group includes:
Variety “Preference” with pink flowers.
Dark Red Honker.
Giant white Alltami Apollo, etc.
Miniature, so-called dwarf dahlias, have recently become one of the leading areas of breeding. About 100 varieties suitable for growing in flowerpots and pots have already been created.
Unlike ordinary dahlias, dwarf dahlias have a longer period of laying buds, renewal and maturation of tubers, therefore, in the fall, before frost, the plants must be placed in a flowerpot for growing in a warm room. But on the other hand, having planted tubers in pots in April, already in mid-June you can admire their flowering.
Dwarf dahlias, like their tall counterparts, are: spherical (Ohio) , cactus (Red Pigmy) , decorative (Virginia) , collar (Alstergruss) , anemic (Inca) or non-double (Sweetheart) .