First, it should be divided according to whether there is poisonous gas or venom. For example, cordate telosma will emit a large number of particles that strongly stimulate the sense of smell at night, which has adverse effects on patients with heart disease and hypertension. The flowers of oleander are poisonous, and the fragrance of flowers makes people fall asleep easily, which reduces human function. Tulip flowers have soil alkali, which is easy to fall off when exposed to hair too much. This is a fierce tree and should not be planted.
The second is to discuss the bad luck with the shape of the tree, such as "the big tree is eccentric, and the name is ruined by gas pain", "the tree bends over and the money is gone" and "the tree is like a lying cow, and it is sick". All ugly, dignified and abnormally developed trees are fierce. I'm afraid this is a psychological effect or a traditional humanistic aesthetic concept at work.
As for auspicious tree, it is determined according to plant characteristics, meanings and even homophones. In real life, people tend to hold this view, such as palm, citrus, bamboo, Toona sinensis, Sophora japonica, sweet-scented osmanthus, Ganoderma lucidum, plum, banyan, jujube, pomegranate, grape, begonia and other plants are auspicious plants, while peach, willow, wormwood, ginkgo, cypress, dogwood and soapberry are all auspicious plants.