What is universal? -The origin of universal.

The clump formed after the sap of trees solidifies is dark brown, solid and heavy, and sinks when entering the water, so it is called agarwood. Dongguan is the most prosperous place to grow agarwood, so it is called Vientiane. Guanxiang was born in a land mixed with yellow mud and sand, with leaves like boxwood and seeds like forsythia. I planted it, and it will be born soon. After four or five years, the tree will be cut down, leaving only a ruler to cover the soil, and let it dig the ground and chisel a few pieces in October every year for the first two or three years. The old incense head is as hard as stone, and it is not easy to rot even if it is eroded by rain. Some old incense heads are stuck by the light of the sun and the moon, and some balsams are caked, which is called knots. Some fragrant trees rot after hundreds of years. If you rub them with your hands like mud, lumps will appear on the scholar's body, which is called cooked knots. The Notes of Eastern Guangdong written by Li Diaoyuan, an inspector of the Qing Dynasty, said that the value of incense knots is more expensive than gold. In addition, the bark of Vientiane is white and thin, and the fiber is elastic. It has been the raw material for making high-grade paper since ancient times. Paper made from Vientiane tree is collectively called honey scented paper and scented paper. Official fragrance is the raw material of many ancient perfume products, and it is this kind of fragrance that people burn when they "smoke clothes and sit still". Guanxiangshu has a long history in Dongguan. The Forbidden City in Beijing still retains the tribute from Dongguan County. According to historical records, in the Tang Dynasty, Guanxiang was introduced from abroad. In Song Dynasty, tillers were widely planted in Guangdong, especially in Wan Yi. The "Dongguan County Records" edited by historian Chen at the end of the Qing Dynasty records: "Since the Ming Dynasty, Vientiane is more important than the world." Because the soil around Dongguan is especially suitable for the growth of Vientiane trees, the unearthed spices have the best quality and are well-known throughout the country, which is a good tribute. Guanxiang is a famous local product from Ming Dynasty to the middle of Qing Dynasty. According to the "Dongguan County Records", "Smile with fragrance, distinguish the scholars first, and the soil should be right. Baishiling, Chicken Wingling, Baihuadong and Niumian Stone will do, but if you go down in Wushikeng, you will go on. " Liaobu is also one of the producing areas of Wanxiang. Although it was not famous for producing incense, it relied on Hanxi River as a commercial port, forming the largest distribution center in Wanxiang at that time. At that time, most of the export compartments were concentrated in Liaobu and then transported to Tsim Sha Tsui, Kowloon. They were shipped to Guangzhou through the wharf dedicated to transporting incense, exported to Suzhou, Hangzhou and Shi Jing at that time, and even exported to Southeast Asia and Arabia. During the Ming and Qing Dynasties, Liaobu once formed thirteen professional streets, one of which was Yaxiang Street, which was a bazaar in Vientiane at that time and has been in use ever since. "Guangdong Xinyu" records the situation that Guanxiang incense was exported to the north when it was in full bloom: "Guanxiang incense rose to the north, although it was worse, it was fragrant and stained with frost and snow. When the compartments were popular, tens of thousands of pieces of gold were sold every year. Susong area, every year in the middle and autumn, burned with yellow ripe flowers, smoked on the moon. The accumulation of Guanxiang was exhausted overnight, so many people in Wanguan started with incense. " It is conceivable that the Liaobu customs trade was so prosperous at that time. Before and after liberation, Guanxiang was cut down indiscriminately, which made Dongguan, once full of mountains and full of green, on the verge of extinction. At present, in Dongguan, the symbolic plant Wanxiang has been hard to find. Except for a few wild Wanxiang in some villages' geomantic forests and primitive secondary forests, even many native Dongguan people only know its name, but they can't see its beauty. At the end of 2005, a century-old wanxiang tree was discovered in Yayao Village, Huaiye, Humen Town. This is the only 100-year-old wanxiang tree found in this town. 2/kloc-today in the 20th century, Dongguan has established the strategic goal of building a famous modern manufacturing city, an ecological green city and a new cultural city, which has set off a new upsurge of cultural construction, continuously excavated historical and cultural resources, and revived the Vientiane tree after years of silence. At present, the research on the breeding and cultivation of Guanxiang is in full swing. Dongguan Botanical Garden has set up a special Wanxiang Garden, which specializes in the propagation and cultivation of Wanxiang. At present, more than 4,000 seedlings of Guanxiang have been successfully cultivated, and it is planned to jointly carry out research on Guanxiang with the Agricultural College of South China Agricultural University. A large number of elephant trees have been planted as street trees near the "Green World" plant park. In order to solve the technical problem of rapid cultivation of Guanxiang in large quantities as soon as possible, Dongguan Institute of Forestry Science has begun to organize scientific research to study the tissue culture of Guanxiang. Party and state leaders planted Vientiane trees in Songshan Lake Science and Technology Industrial Park, town cultural squares, urban roads and green communities. Known as the characteristics and pride of Dongguan, "Vientiane" will soon be fragrant again on the land of Dongguan.