Rhododendron —— Beauty in Flowers
Scientific name: Rhododendron
British name: Indian azalea
Alias: Yingshanhong, Shan Shiliu, Mountain Wandering, Red Wandering, Jindalai.
Family name: Ericaceae
Origin and habit:
There are about 900 species of rhododendron, and about 850 species are produced in Asia. There are about 530 species in China, which are distributed in all communities except Xinjiang. There are about 280 species in New Guinea and Malaysia, almost all of which are epiphytes. In addition, there are 24 species in North America, 9 species in Europe and 1 species in Oceania. There are many kinds of rhododendrons, which vary greatly, including evergreen trees, small trees, evergreen shrubs and deciduous shrubs. Habits are also very different, but most species are produced in high altitude areas, preferring cool and humid climate and avoiding extreme heat and dryness. The soil is required to be rich in humus, loose and moist, and the ph value is between 5.5 and 6.5. Some species and horticultural varieties have strong adaptability, drought tolerance and barren tolerance, and can grow in the soil ph value of 7-8. Rhododendron has certain requirements for light, but it is not resistant to exposure. In summer and autumn, there should be trees or shade sheds to keep out the scorching sun. Generally, bamboo shoots are picked in spring and autumn, mainly bamboo shoots. The optimum growth temperature is 15 ~ 25℃. When the temperature is higher than 30℃ or lower than 5℃, the growth tends to stagnate. There is a short dormant period in winter.
Morphological characteristics: There are many kinds of rhododendrons with different shapes. From big trees (more than 20m in height) to small shrubs (only 10cm-20cm in height), the trunk is erect or creeping, and the branches alternate or alternate.
The varieties often cultivated in China are: Mao Juan, Xia Juan, Xijuan, Wild Tobacco, Rhododendron rubrum, Mayflower and Rhododendron yunyin.
China is the distribution center of rhododendron, with about 460 species distributed in all provinces except Xinjiang and Ningxia. Southeast Tibet, southwest Sichuan and northwest Yunnan are the most concentrated producing areas, with more than 100 species respectively, and Yunnan alone accounts for more than half of the rhododendron species in China. Many countries in the world are imported from here. When azaleas are in full bloom, it is the time when azaleas are singing. The ancients left many poems and beautiful legends, and there was a custom of taking flowers as festivals. Rhododendrons are mostly shrubs or small trees, and have their own living habits and forms because of different ecological environments. The smallest plant is only a few centimeters high, cushion-shaped, and lives close to the ground. The largest is as high as tens of feet, standing tall and spectacular. Rhododendrons can be divided into deciduous and evergreen. Small leaves, often big green leaves. The colors of flowers are red, purple, yellow, white, pink and blue. Like cool, moist and cold-resistant, it grows mostly on slopes, alpine meadows, forest margins, stone walls and swamps at an altitude of 1000- 1400 meters. In addition to ornamental purposes, some flowers can be used as medicine or extract aromatic oil, some flowers can be eaten, bark and leaves can be made into baking glue, and wood can be used as handicrafts. Rhododendron alpine has developed roots and is a good plant for soil and water conservation.
Note: the plants and flowers of Rhododendron flavum contain toxins, which will cause poisoning after eating by mistake; The flowers of Rhododendron leucocephala contain tetracyclic diterpenoids, which cause vomiting, dyspnea and numbness of limbs after poisoning.
Key points of propagation: sowing, cutting, grafting and layering can be used for propagation.
Uses: Rhododendron is an excellent bonsai material with lush leaves, beautiful and colorful flowers, strong germination, pruning resistance and strange roots. Gardens are most suitable for planting in clusters near forest edges, streams, Chi Pan and rocks, or scattered under sparse forests. Rhododendron is also a good material for hedges, and Mao Juan can also be pruned and cultivated into various forms. Rhododendron Garden has its own characteristics. Rhododendron can be used as medicine, and some can be eaten. The flower acid of azalea is non-toxic and can be eaten raw. The flowers of Rhododendron giganteum and Rhododendron pachydermum are beautiful vegetables for people in central Yunnan. The branches, leaves and flowers of Mao Dujuan are soaked and retted, which can be used as insecticidal pesticides; Rhododendron in Xing 'an, etc. , which can be used in pharmacy. Some kinds of bark and leaves are rich in extracts, which can extract tannin extract; Rhododendron's wood and root pocket are delicate and tough, which can be used for making bowls, chopsticks, pots, bowls, pipes, roots and other daily labor and art. Du Juanhua is sweet, slightly bitter, flat and fragrant, and has certain medicinal value in medicine. It can dispel wind and dampness, regulate menstruation and blood, soothe the nerves and remove dryness. People often cook this flower with pig's trotters, which can cure female leucorrhea. Long-term drinking has the effect of whitening and removing spots.
Function of plant dyes: As a foil for flowers, the function of branches and leaves of rhododendron has not been paid attention to. It is actually a natural dye. Uses: branches and leaves.
In the domestic environment, potted azaleas are better. It is appropriate to choose early spring or late autumn as the time to go to the basin. Rhododendron roots expand slowly, so it is advisable to use 3-inch pots for 1 ~ 2 years, 4-inch pots for 3 ~ 4 years, change pots 1 time every 3 ~ 5 years, and trim roots at the same time. Water, according to the specific situation of flexible grasp. When the temperature is low, there is little water; In high school, you should water while drying, but you must not accumulate water. Fertilization should be thin and diligent. For 2 ~ 4-year-old seedlings, in order to accelerate the formation of plants, the methods of coring and bud picking are often used to promote the growth of new branches; After the plant is formed, the diseased branches, weak branches and overlapping branches are mainly cut off, and thinning is the main method.
Rhododendron, also known as Rhododendron by the masses, refers to all kinds of red rhododendron, describing its bright red brilliance to make the mountains red. In fact, which rhododendron is red, today's plant taxonomy only takes "Yingshanhong" as one species (including many cultivated varieties). Rhododendron is naturally distributed in temperate and subtropical regions of the northern hemisphere. There are more than 800 species in the world, including more than 600 species in China and nearly 300 species in Yunnan. Undoubtedly, China is the origin of Rhododendron, and Yunnan is its distribution center.
Rhododendrons are mostly shrubs and small trees, one or two meters high. For ten days, Rhododendron and Rhododendron purpurea flowers crawled on the rocky ground, only a few centimeters high. There are dozens of feet of azaleas and thousands of flowers. The top of the azalea is an umbrella-shaped tidbit, which consists of several bell-shaped or funnel-shaped flowers, just like a full hydrangea. Most leaves are leathery. They are as big as a batch of handles and as small as nails. There is also a rhododendron with sharp leaves, more than 70 cm long and 20 cm wide. The fruit is a capsule and the seeds are as fine as dust. Sowing must be carefully managed before seedlings can be unearthed.
Rhododendron grows in the mountains, Zhongshan, low mountains and fields at an altitude of 800-4500 meters in Yunnan, with the most abundant species in the mountainous areas of western Yunnan. Especially in the alpine wetlands. Many kinds of evergreen rhododendrons, such as yellow rhododendron, Rhododendron glabra, Rhododendron globosa and Rhododendron latifolia, often form dense rhododendron flowers and pure forests, and there is a "sea of flowers" spectacle of rhododendrons from 10 to 20 kilometers. The flowering period of azaleas varies with climate and varieties. The warm areas in the low mountains are mostly open in February-March, the cool areas in the middle mountains are mostly open in April-June, and the cool areas in the high mountains are mostly open in July-August. Due to the variety, wide distribution and complex ecological environment, the posture and charm of rhododendron flowers are also diverse: some branches are sparse, and some branches are dry; Some are lush, handsome and tall, and some are vigorous and quaint. Its patterns and colors are even more colorful: crimson like fire, golden yellow, crystal blue like treasure, or with spots or stripes, pink, magenta, orange, lavender, yellow with red, red with white, white with green, which is really ever-changing and spectacular. Some have heavy make-up, gorgeous clothes, some have light white, some have red lips and white teeth, and some have refreshing fragrance. They really have their own charm and grace.
Due to the important value of rhododendron in gardens, China's rich and diverse social rhododendron resources have long been coveted by western countries. As early as the beginning of19th century, they sent people to Yunnan many times to collect specimens and seeds, which cost a lot. Today, hundreds of azaleas boasted by the Royal Botanical Garden have been collected and cultivated in Yunnan and have already grown into forests. When the buds are in full bloom, English women and men are touching.
19 19, the British collector frith accidentally discovered the "cuckoo giant"-Rhododendron dendrobii on the west slope of Gaoligong Mountain in Tengchong, Yunnan. Greed drove him to hire a coolie, settle down, raise an axe, cut down the 280-year-old rhododendron which is 25 meters high, 87 centimeters high, and brought back a disc-shaped wood specimen, which is still displayed in the British Museum in London. But 63 years later, in February of 198 1, scientists discovered the highest and largest azalea king known in the world. According to further investigation by Tengchong Forestry Bureau, there are still 12 rhododendrons with DBH above 1 m, the largest of which is 1, with a height of 25m, a diameter of 3.07m and a tree age of over 500 years. The inflorescence of Rhododendron grandiflora is a very beautiful flower cluster, water red. Each inflorescence consists of 20 ~ 24 bell-shaped flowers, with a length of 6 cm-8 cm, a diameter of 6 cm and a inflorescence diameter of 25 cm. This indomitable tree-Rhododendron, with its lush canopy and brilliant flowers like clouds, is the pride of Yunnan and the pride of the motherland!
Rhododendron azalea is a common rhododendron, which is named after it blooms all over the mountains. It is distributed in the mountainous areas above 500 meters above sea level such as Xijiang, Fenghuang Mountain, Zhuangkou and Lanshan in Huichang County, Ganzhou City, Jiangxi Province. Yingshanhong is known as "the king of woody flowers". Scholars at all times and all over the world wrote many beautiful poems praising Yingshanhong, such as a poem by Yang Wanli in the Song Dynasty, "Why don't you watch the spring breeze in the famous garden?" Every day, Jinjiang is like a brocade, and Qingxi shines on the mountains. "Praise the simple and tenacious vitality of Yingshanhong.
Climb the lush Yantou Mountain, and you will see the flaming azaleas steaming among the green hills and trees, in clusters, blooming so warmly and beautifully. Flowers are like red agate, standing upright in the wind, delicate and charming, with dense petals. The petals are very close, very close, attracting countless bee discs to fly around. Every flower is ethereal and subtle, picturesque and beautiful, which makes people linger.