The traditional Chinese medicine Tuncao, also known as Daokoucao, is a highly invasive weed with strong reproductive capabilities. Tuncao can cause significant damage to plants. What are the morphological characteristics of Tuncao?
Image of Tuncao
【Harm caused by Tuncao to plants】
1. Nutrient absorption
Tuncao usually grows in large clusters and has extremely strong regenerative and reproductive abilities. It not only makes the soil dry and infertile but also blocks sunlight due to its tall size, making it difficult for other plants to grow and reproduce. Its strong reproductive capabilities make it difficult to eradicate once it starts growing.
2. Transmission of diseases and pests
Do you know what causes sunflower leaf spot disease and soybean pests? Part of the reason is caused by Tuncao. This is another harm caused by Tuncao, as it can transmit diseases and pests.
When Tuncao fruits are mixed with other plants, it can lead to terrifying spread. For example, clubroot disease in cabbage is caused by Tuncao.
Image of Tuncao
【Morphological characteristics of Tuncao】
Tuncao is an annual herbaceous plant, ranging from 20 to 150 centimeters in height. The stem is erect with conical branching in the upper part, having edges and sparsely rough hairs.
The lower leaves are opposite, with short petioles, bipinnately divided, and the lobes are narrow, ranging from elliptical to lanceolate, with entire margins and obvious midveins. The upper surface is dark green, with fine short appressed hairs or nearly hairless, and the lower surface is grayish green, with dense short rough hairs. The upper leaves are alternate, sessile, and pinnately divided.
The male head inflorescence is hemispherical or ovoid, with a diameter of 4 to 5 millimeters, having short peduncles and hanging down. They are densely arranged in terminal panicles. The involucre is broadly hemispherical or disc-shaped, with all involucral bracts fused, unribbed, and with wavy rounded teeth along the edges, slightly rough-haired.
The receptacle has bristle-like receptacle scales. Each head inflorescence has 10 to 15 sterile florets. The corolla is pale yellow, 2 millimeters long, with a short tubular base and a bell-shaped upper part with wide lobes. The anthers are oval-shaped. The style does not split and swells at the top, forming a brush-like structure.
The female head inflorescence is sessile, located under the male head inflorescence or in the axils of the lower leaves, solitary or clustered in umbels, with one fertile female flower without bracts, the involucre closed, with fused involucral bracts, inverted ovate or oblong-ovate, 4 to 5 millimeters long and approximately 2 millimeters wide, with a conical mouth enveloping the style, and 4 to 6 thorns below the top, slightly rough-haired. The style is deeply divided into two filiform parts, extending out of the mouth of the involucre.
The achene is inverted-ovate, hairless, and hidden in the hard involucre. The flowering period is from August to September, and the fruiting period is from September to October.
