Cornflower（Centaurea cyanusL.），Annual or biennial herb of the genus Centaurea in Compositae.Centaurea branches from the middle of the stem, the whole plant is gray white, densely curly;The leaf blade is lanceolate, and the entire margin is pinnately divided;The head is terminal and arranged into a panicle. The bracts are about 7 layers in total. The side flower is larger than the central disk flower, and the front end is lobed.[10]The flowering period is from April to May.[11]The name of cornflower comes from Japan, because the flowers shoot like arrows in all directions and the whole shape radiates like wheels.[12]
Cornflower is native to southeast Europe,[11]It is mainly distributed in the Mediterranean region and southwest Asia.[13]Cornflower has strong adaptability. It likes to have enough sunshine, but it is cold resistant rather than wet. It likes cold and cold, and avoids hot.It likes fertile, loose and well drained sandy soil.[14]Cornflower is propagated by sowing.[15]
As a traditional plant medicine of European folk medicine, cornflower is mainly used to treat ophthalmic inflammation.Pharmacological studies showed that cornflower has anti-inflammatory, antibacterial, anti-tumor, diuretic and other effects.[16]Centaurea can be used for flower bed, grass border or potted flower appreciation, and large natural clumps.High type varieties can be matched with other grass flowers to arrange flower beds and flower borders, and can also be used as cut flowers.[17]Cornflower is the national flower of Germany and a symbol of happiness.[11]
Because flowers shoot out in all directions like arrows, and the whole shape radiates like wheels.[12]
morphological character
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Cornflower
Centaurea, annual or biennial herb of Centaurea in Compositae.Height 30-70 cm or more, erect, branched from the middle of the stem, rarely unbranched.[10]
All stems and branches are grayish white, covered with thin arachnoid curls.The basal leaves and the lower stem leaves are long elliptic oblanceolate or lanceolate, undivided, with no serrations or sparse serrations at the edges to pinnate split at the big head, 1-3 pairs of lateral lobes, long elliptic lanceolate, linear lanceolate or linear, with no serrations at the edges, large top lobes, long elliptic oblanceolate or lanceolate, with small serrations at the edges.Middle stem leaf linear, wide linear or linear lanceolate, 4 long-9 cm, 4-8 mm wide, the top is acuminate, the base is wedge-shaped, no petiole, the edge of the whole edge is not serrated, the upper stem and leaf are the same shape as the middle stem and leaf, but gradually smaller.Both sides of all stems and leaves are heterochromatic or nearly heterochromatic, green or grayish green on the top, sparsely covered with spider silk or depilated, and grayish white on the bottom, covered with thin hairs.
Most or a few of the heads are arranged into corymbs or panicles at the top of the stems and branches.The involucre is elliptic, 1-1.5 cm in diameter, with sparse spider silk hairs.The involucral bracts have about 7 layers. All involucral bracts are elliptic from outside to inside and long elliptic. The outer and middle layers, including the top appendages, are 3-6 mm long and 2-4 mm wide. The inner layer, including the top appendages, is 1-11 cm long and 3-4 mm wide.There are light brown or white appendages at the top of all bracts. The appendages in the middle and outer layers are larger, and the appendages in the inner layer are larger. All appendages are short and downward along the bracts, and the edges are fimbriate serrated.The edge flower is larger than the central flower, and the front end is slightly split, blue, white, red or purple. The eaves are 5-8 split, and the flower is light blue or red.[10]
Achene elliptic, 3 mm long, 1.5 mm wide, with thin stripes, sparsely white pilose.The crown hairs are white or light earthy red, in two rows, the outer row is multi-layer, gradually grows towards the inner layer, up to 3 mm, the inner row is one layer, very short;All crown hairs are bristly.The flowering period is from April to May.[11]
Distinction of recent species
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Color lead painting of cornflower
There is another similar species, namely Cdepressa MB. （Fl. Taur.-cauc. 2： 346， 1808； DC.， Prodr. 6： 578， 1837； Ldb.， Fl. Ross. 2（2）： 698， 1845-1846： Boiss.， Fl. Or. 3： 635， 1875； Czer. in Fl. URSS 28： 415， 1963.） ， According to CK. According to records, it is distributed in Yining, Xinjiang, China and western Tibet.It is different from cornflower in that its inner row of crown hairs and bristles are membranous;The setae of row crown hairs are 8 mm long.Its type specimen is from Georgia.The specimen is not found, and the above documents and brief distinguishing features are hereby issued as a note.
Distribution range
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Cornflower
Cornflower is native to southeast Europe,[11]It is mainly distributed in the Mediterranean region and southwest Asia[13]In North America, China is mainly planted in parks, gardens and campuses in Xinjiang, Qinghai, Gansu, Shaanxi, Hebei, Shandong, Jiangsu, Hubei, Guangdong and Tibet.Xinjiang and Qinghai may haveNaturalizationYisheng.
Growth habit
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Cornflower has strong adaptability. It likes sunshine, but is not resistant to humidity and cold. It likes cold and cold, and avoids heat. It must be planted in a place with sufficient sunshine and good drainage, or it will often die due to humidity.It likes fertile, loose and well drained sandy soil.[1][14]
Cultivation technology
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Cornflower is propagated by sowing.[15]
Key points of cultivation
cultivate
Sowing in spring and autumn is preferred.Sow in the prepared seedbed in the middle and last ten days of September, cover the soil with no seeds, slightly compact, cover with grass, water enough, keep the soil moist, and remove the grass after germination.When the seedlings have 6-7 leaflets, they can be transplanted or planted, with a plant spacing of about 30 cm. After planting, apply 5 times of water to the decomposed human feces and urine every 10 days or half a month, and stop applying fertilizer in March of the next year to wait for flowering.For potted plants, the soil should be loose and fertile. It is best to use garden soil, rotten leaves, grass ash, etc. to prepare mixed soil. When seedlings have 6-7 leaves, they should be transplanted for the first time, and short seedlings should be replaced in tube pots.[2]
Seedling raising: loose and fertile soil is selected as the bed, covered with about 0.2cm of soil. Cultivation: transplant when the seedling leaves reach 6-7, and pot plant one plant every 13-17cm.After the seedlings survive after planting, they should be pinched once to promote more branches and flowers. On the contrary, if there are too many branches, part of the lateral buds should be removed when necessary to obtain larger flowers.Because of its taproot nature, it is advisable to directly sow in autumn and cover the open ground for overwintering, and flower in early summer. If it winters in a cold bed, it can flower in late spring. Spring sowing should be sown as early as possible.It blooms in June.
Cultivation site: Cornflower is native to European fields, so it is slightly cold resistant and likes coolsunshineAdequate places.
Soil use: I prefer loose and fertile sandy loam with good drainage.Cultivated soil should be well drained and ventilated as far as possible. If the soil is viscous, it can be improved by mixing 30-40% snakewood chips or pearl stones.
watering: In principle, watering once a day is enough, but when the summer is dry, it can be done once in the morning and once in the evening to keep the pot soil moist and reduce the temperature of pot plants, but no ponding is allowed.
Fertilization: Cornflower likes to apply more fertilizer, and three element diluent should be applied once a month during the growth period.If the leaves are too luxuriant, the proportion of nitrogen fertilizer should be reduced, and more phosphorus and potassium fertilizer should be applied before flowering to obtain larger and beautiful flowers.
Flowering period management: centaury can naturally send out lateral branches. If there are more lateral branches, the flowers will be smaller. If necessary, part of the lateral buds can be removed. If only smaller branches are left, larger flowers can be obtained.CornflowerPerennial plant, in winterSunshine timeShort, if used at nightPlant lampSupplementary lighting can make flowering earlier.[3]
Administration
Cornflower
Cornflower likes sunny and cool climate, avoids hot summer, and is suitable for fertilitylooseSoil.Because of its direct root, it is suitable for live broadcast.The autumn sowing is for early flowering, which can be wintered in the cold bed, and can blossom at the end of spring.Because cornflower is not transplant tolerant, it must be transplanted with soil mass, otherwise it is not easy to slow down the seedlings.After planting, apply 5 times of water to the decomposed human feces and urine every 10 days or Douyue, and stop applying fertilizer in March of the next year for flowering.
For potted plants, the soil should be loose and fertile. It is best to use garden soil to rot leaves, plant ash, etc. with mixed soil. When seedlings have 6-7 leaves, carry out the first transplantation;After growth, at least change to a three tube pot. Because the cornflower has a straight root system, the large seedlings cannot tolerate transplanting.It can be continuously buried in the soil for winter, and taken out in the first ten days of March. Fertilization should be carried out frequently, and stopped when the buds appear.
It has strong cold resistance and can be planted in the open field in East China. It can survive the winter only if it is covered in North China;Likes fertile and loose soil;Like sunshine;Self broadcasting;Strong adaptability and easy cultivation.When cultivating cut flowers, we usually use greenhouse to hasten flowers: sowing in August, planting in September, and producing flowers in February of the next year.Generally, the warm land in Guannei is sown in August September, and the open land is covered for winter in the next yearearly springPlanting, flowering in early summer.Spring sowing in greenhouses in Northeast China.
Because the root of cornflower is taproot and there are few lateral roots, it is necessary to carry soil when transplanting small seedlings, and it is difficult to survive when the seedlings are large, so they are often directly seeded in spring.The cornflower can also be self sown and propagated. In addition, the cornflower likes to be closely planted, otherwise it will grow poorly.
Prolong florescence
The cornflower is rich in color and unique in shape. It is a good material for ground, potted and cut flowers.In order to extend the flowering period of cornflower, spring sowing and summer sowing can also be used in addition to autumn sowing.If sown in April to May, flowers will blossom in July to October of the same year.In July, seeds matured in the same year are used for sowing, and flowers can blossom after September. Open field cultivation can last untilFirst Frost。In the middle and late October, the plants planted in the ground will be transplanted into the flower pot for winter, or directly sown in the pot in August, and entered into the house before winter.In winter, as long as the room temperature is kept at 8~15 ℃, proper watering and a small amount of thin compound fertilizer are applied and placed in a sunny place, the cornflower can also blossom.This method of sowing by stages and batches can effectively extend the flowering period of cornflower.
matters needing attention
Cornflower
Cornflower is strong, cold resistant, and likes sunshine. It requires fertile, loose and well drained soil.Generally, it is directly seeded on the seedbed in September, and can overwinter in the open ground in the south of central China. There is no need to be cold proof in winter. It is transplanted in November or early March of the next year.The autumn sown seedlings in North China should be transplanted once when they grow 2-3 true leaves. The seedlings should be planted in the open before winter, covered with cold proof materials in winter, and planted in the open in the early spring of the next year.Base fertilizer shall be applied before planting.Because the cornflower has a straight root system and is not tolerant to transplant, it must be transplanted with a large soil mass.
The stem of cornflower is thin and weak, so it is easy to lodging. Therefore, the planting distance should not be too dense. It is necessary to prevent overdense growth and poor ventilation from causing lodging.At the seedling stage, topping and pinching are required to promote more branches and dwarf the plant, so as to have more flowers and beautiful plant shape.Top dressing once every 20 days during the growth periodLiquid fertilizerHowever, it should be noted that more nitrogen fertilizer should not be applied, and more phosphorus and potassium fertilizer should be applied to make the stems strong and colorful.At the same time, watering should be appropriate, not too much. In rainy season, attention must be paid to timely drainage, otherwise it will cause root rot and affect the normal growth of plants.[2]
Flower seed collection
Flower seed collection
When the inflorescence just withers and turns yellow, the seeds can be harvested.If the inflorescence is too mature and the seeds are easy to scatter, the whole plant can be cut when most inflorescences are withered and yellow, threshed after drying, and stored in a cool and dry place.The seeds have the ability of self sowing.
Disease control
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Sclerotinia disease
Sclerotinia disease
The pathogen is Sclerotinia sclerotiorum.This disease mainly affects the base of the stem. When the temperature is high, the stem often appears watery brown spots. When the condition is serious, the affected part turns gray white, and then the tissue decays, and the upper stem and leaf wither. This disease is most likely to occur in the humid environment with an ambient temperature of about 15 ℃ in spring and autumn.The control method is to avoid too dense planting;Immediately pull out the diseased plants and burn them in a centralized way;When the disease is serious, the middle and lower parts of the plant can be sprayed with 1000 times solution of 70% tobuzin wettable powder.
downy mildew
downy mildew
Symptoms: Irregular grayish green to reddish disease spots appear on the surface of the susceptible leaves, and the disease spots on the back of the leaves are covered with a layer of downy mildew, leading to the withering of the leaves.
Pathogen: Bremialactucae Regel, a fungus belonging to the subphylum flagellates, oomycetes, downmold, and Pedicularis.
Pathogenesis: The pathogen overwinters in the diseased tissue with oospores.In the second year, oospores germinate and produce germ tubes for infection and damage.Young plants are susceptible to disease.High humidity is conducive to disease occurrence.
prevention and cure:
The diseased plants shall be pulled out in time for centralized treatment.
The plants are not densely planted, and good ventilation and light transmission conditions are maintained.
Chemical prevention and control: when the disease occurs, it can be sprayed with 1:1:100 Bordeaux solution, or 500 to 800 times of 65% mancozeb wettable powder, or 800 to 1000 times of 25% Swiss mold, or 200 to 300 times of 40% Etophosphate aluminum.[4]
Crinkle disease
Crinkle disease
Symptoms: The leaves of susceptible plants are twisted and atrophied, and the veins are necrotic.
Pathogen: The pathogen is Artichoke curly dwarf virus.The virus passivation temperature is 55-60 ℃, the dilution limit is 0.00001-0.001, and the virus retention period in vitro is 2-3 days.
Pathogenesis: The virus is infected through juice contact, and no vector is found.The virus has a wide range of hosts. In addition to cornflower, it can also infect thistle, jerusalem artichoke, sunflower, zinnia, etc.There are chlorotic spots on the sunflower with light brown necrotic edges.Local spot on zinnia.The pathogenesis is still unclear.
prevention and cure:
If any diseased plant is found, it shall be pulled out immediately and destroyed collectively.
During gardening operation, try to avoid contact infection of juice, and sterilize hands and tools.[5]
Key values
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Medicinal value
As a traditional plant medicine in European folk medicine, cornflower is mainly used to treat ophthalmic inflammation.Pharmacological studies showed that cornflower has anti-inflammatory, antibacterial, anti-tumor, diuretic and other effects.[16]
Gardening
Centaurea can be used for flower bed, grass border or potted flower appreciation, and large natural clumps.High type varieties can be matched with other grass flowers to arrange flower beds and flower borders, and can also be used as cut flowers.[17]
Gardening
High quality plants are tall and straight with long pedicels, which are suitable for cutting flowers and flower diameter materials.The dwarf plant is only 20 cm high and can be used forFlower bed, grass border or potted flowers.A vast expanse of natureClump planting。High type varieties can arrange flower beds and borders in proportion to other flowers.It can also be planted on the roadside or in the lawn. The plant type is elegant, and the flowers are beautiful and natural.Still can doCut flowers 。
Beauty efficacy
It can nourish the face, relax the mood, help digestion, and make urination smooth.Cornflower Dew is a mild natural skin cleanser,Floral waterIt can be used to maintain hair and moisturize skin;It can help digestion and relieve rheumatism pain.Helps to treat stomach pain and preventgastritisGastrointestinal discomfort, bronchitis.It is a flower that fears neither heat nor cold, so it is difficult to plant it well in Taiwan in summer, unless it is planted in high and cold areas.
make tea
Single brew, suitable for matching with green tea.Take four teaspoons of cornflower and brew with boiling water.The lavender tea juice can be added with a little honey to enhance the flavor.
Plant culture
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Flower language
The flower language of cornflower is: meet and happiness.
Meticulous and elegant. It also represents happiness
national flower
Cornflower is the national flower of Germany and a symbol of happiness.[11]
Queen Louis, the mother of Prussian Emperor William I, was forced to leave Berlin during a civil war.On the way to escape, the car broke down. When she and her two children stopped at the roadside and waited, they found blue cornflowers blooming on the roadside. She made a wreath of these flowers and wore it on the chest of nine year old William.Later, William I was crowned the German emperor, and he still liked cornflower very much, thinking it was a lucky flower.The cornflower also inspires people to study carefully and modestly.[6]
Eye protector
Such a legend is widely spread among German people.Arminius, the great ancient hero, unfortunately suffered from eye disease during an expedition. One night, Ares, the god of war, came to Arminius' dream and told him that the blue flowers blooming on the roadside in the morning could cure his eyes.The next day Alminius found the blue flower on the roadside and smashed it for his eyes.Soon, Alminus recovered his eyes and returned triumphantly.So he called cornflower "eye protector" and spread it widely.[7]
