Alias: parasitic bean, rootless grass, yellow silk, golden silk, cold silk, eight thousand fields, eel vine.
English name: China Dodder
Family name: Convolvulaceae
Annual parasitic herbs. The stems are filiform and orange. There are no leaves. Flowers clustered with membranous bracts outside; Calyx cup-shaped, 5-lobed; The corolla is white, twice as long as the flower, with 5 cracks at the top, and the lobes often bend outward; Stamens 5, filaments short, alternate with corolla lobes; Scale 5, suborbicular. Ovary 2-loculed, 2 ovules per locule, 2 styles, head to head. Capsule nearly spherical, completely surrounded by corolla when mature; The seeds are light brown. The flowering and fruiting period is July -65438+ 10.
It is produced in Lianyungang, Qiuxian, Tongshan, Baoying, Nanjing, Wujiang and other places. It grows on the roadside and riverside of hillsides and is mostly parasitic on plants such as Leguminosae, Compositae and Polygonaceae. Distributed in North China, East China, South China, Northwest China and Southwest China. Cuscuta chinensis has the characteristics of gregarious, so it is easy to identify that seeds contain fatty oil and starch in the field; It can also be used as medicine, which is a nourishing and astringent medicine to treat impotence, nocturnal emission and enuresis.
Cuscuta japonica
Scientific name Cuscuta japonica
Cuscuta chinensis belongs to the genus Cuscuta of Convolvulaceae. English name dodder, Chinese name is bean parasitism and rootless grass. Annual parasitic herbs, lacking the structure of roots and leaves. The stems are climbing, silky and yellowish, and the plants have haustorium attached to the host. There are many flowers, which are clustered together and have short pedicels. Calyx 5-lobed, about as long as corolla. Corolla 5-lobed, short bell-shaped, about 2 mm long, 5 stamens and 2 styles. The capsule is spherical, slightly flat, and the seed shape changes greatly and is brown. Cuscuta chinensis seems to prefer sunny open environment, such as hedges at home, slope protection on shoulders and bushes by the sea, which are ideal parasitic environments for Cuscuta chinensis. Cuscuta Cuscuta is gregarious, so it is easy to identify in the wild. The host range of Cuscuta chinensis is quite wide. Most dicotyledonous herbs (such as Leguminosae, Leguminosae) and some monocotyledonous plants may become parasitic objects of Cuscuta chinensis, so it is like a weed in crop cultivation. However, dodder also has a considerable position in medicine. It can cure all kinds of sores and swelling, nourish and strengthen yellow, so it is also a good medicine of Chinese medicine. When dodder invades plants, it will grow haustorium into plants, absorb nutrients from the host and continue to grow other branches. It can be seen that a dodder can cover a considerable area of crops or plants. The seeds of Cuscuta chinensis are dormant, so once the field is invaded by Cuscuta chinensis, it will cause the problem of being harmed by Cuscuta chinensis for several years in a row. The most convenient way to control Cuscuta chinensis is to use herbicides to inhibit the growth or seed germination of Cuscuta chinensis. The chemical agents that can prevent and kill Cuscuta chinensis are: 2,4.d (two or four places), Miron (Miron), dcpa (Dacaocao), dichlorvos (Dichlorvos), dichlorvos (Dafen), diquat (Tephene), dnoc (Dinitrophenol, Fluclomiphene). In addition, it can be cultivated and watered early before cultivation, so that dodder will die without looking for a host after germination. Adjusting the cultivation period of crops and using herbicides together can achieve good control effect.
Distributed in Shanghai and Hangzhou.
Harmful objects include hibiscus, rhododendron, rose, snow, osmanthus, peony, coral tree, Acer truncatum, Holly, Ligustrum lucidum and so on.
When the seeds germinate, the buds are colorless and filiform and attach to soil particles. At the other end, filamentous dodder is formed, which rotates in the air, entangles the host and forms root suction at the contact point. After entering the host tissue, some cells differentiate into conduits and sieve tubes, which are connected with the conduits and sieve tubes of the host to absorb the nutrients and water of the host. At this time, the newborn dodder died, the upper stem continued to elongate, forming root suction again, the stem continued to branch and elongate to form root suction, and then continued to spread around. In severe cases, the whole host was covered by dodder, which made the damaged plants grow poorly, and some hosts died because of malnutrition and entanglement of dodder.
Morphology: Cuscuta japonica has no roots, leaves and degenerated leaves. Its stem is thick and reddish, growing around and spreading quickly. It can continue to grow after the broken stems form roots. Flowers are pink and fruits are spherical. Each Cuscuta japonica produces 5 000 ~ 6 000 seeds, which are small and smooth and can survive in ten kinds of soil for several years.
In Shanghai, Cuscuta chinensis blooms in September, and the seeds mature in June 5438+ 10, and the seeds fall into the soil for the winter, or fall into the soil in February-March-June of the following year, and germinate one after another, which is harmful after encountering the host. If there is no host, you can live independently 1 month and a half under suitable conditions. Hosts are extensive, mainly woody plants, but also harmful to herbs, spreading rapidly, endangering seedlings, young trees and shrubs, but not the aged bark. Tall trees spread upward through rhizosphere sprouting branchlets or rely on other hosts as bridges.