Tanweed is a highly harmful weed that can easily hinder the growth of other plants due to its strong regenerative ability. Tanweed looks very similar to mugwort, and many people often confuse the two. Now let's take a look at the differences between tanweed and mugwort.
【Growth Characteristics of Tanweed】
Tanweed has a strong regenerative ability. It can grow new roots from its stem, nodes, branches, and roots. It can even form new plants when propagated by cuttings. Even after being removed or cut, the remaining aboveground parts of tanweed can quickly regenerate.
The growth period of tanweed is uneven and overlapping. The emergence period can last from mid to late March until late November, spanning a period of 7 months. Early and late maturing tanweed can have a difference in growth period of more than a month. This is the direct cause of the uneven and overlapping growth period.
Tanweed prefers moist conditions and is afraid of drought. It has shallow root systems and cannot absorb water from deep layers of the soil. It tends to wilt and wither during the dry autumn season, while it thrives in moist areas. It has strong cold resistance.
Mature tanweed can withstand temperatures as low as -3 to -5°C in winter, making it a perennial weed. It grows densely in patches. Since tanweed seeds generally scatter within a radius of 1-1.5 meters around the plant, year after year, it forms dense patches of growth.
Seedling stage. The germination rate of tanweed seeds is 91.49%. Seeds sown at a depth of 0.3-1cm have the highest, best, and fastest emergence rate, while those above 5cm cannot emerge. Seedlings below the fourth pair of true leaves are prone to frost damage, while those above the fourth pair of true leaves have stronger cold resistance. Seedlings show obvious heliotropism.
【Harmful Effects of Tanweed】
The direct harm of tanweed to the human body is caused by the pollen it releases after flowering. The pollen of this weed contains water-soluble proteins, which can be rapidly released upon contact with humans, causing allergic reactions.
Tanweed is the main pathogen of autumn pollen allergy and can cause harmful "hay fever". Mild cases can cause coughing and asthma, while severe cases can cause emphysema, and the infection tends to recur every year and worsen over time.
Tanweed pollen is the main pathogen causing a series of allergic reactions known as "hay fever". The density of tanweed pollen particles in the air can reach 40-50 particles per cubic meter, which can infect the population with hay fever (autumn pollen allergy).
Clinical manifestations of patients include itching of the eyes, ears, and nose, intermittent sneezing, runny nose, headaches, and fatigue. Some may experience chest tightness, shortness of breath, coughing, and difficulty breathing.
Prolonged untreated cases can lead to complications such as emphysema and cor pulmonale, causing extreme pain and even death. Tanweed plants and pollen can also cause some people to suffer from allergic dermatitis and develop "eczema" all over their bodies.
【Differences between Tanweed and Mugwort】
The main differences between tanweed and mugwort are as follows:
Appearance - The external appearance of tanweed is very similar to mugwort. The difference is that the back of mugwort leaves has a grayish-white short hair, and all the leaves of the plant are opposite. On the other hand, the upper side of tanweed leaves is dark green, the back is light green, and both sides have short rough hair.
Odor - When smelling mugwort branches and leaves, there is a distinctive strong aroma, while tanweed has a repulsive grassy odor.
Tanweed is easily confused with mugwort, but it poses certain risks to cultivated plants, wild plants, and human health. It is known to be highly invasive, causing harm to crops and the growth of annual grasses such as Asteraceae and Poaceae.
Tanweed can release various substances that inhibit the normal growth and development of cultivated plants and wild plants. Its pollen contains allergenic substances, which can cause harmful "hay fever" in humans, resulting in coughing and asthma in mild cases, and emphysema in severe cases, even endangering lives.
