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The toxic secret hidden in the blackboard tree: Do you know how much it affects your body?
The blackboard tree (Alstonia scholaris), also known as the scholar's tree, milk tree or devil's tree, is an evergreen tropical tree belonging to the Solanaceae family. It is native to southern China, tropical Asia (mainly the Indian subcontinent and Southeast Asia) and Australasia, widely used as an ornamental plant. Although the blackboard tree is a poisonous plant, it is used in traditional medicine to treat a variety of illnesses and ailments. In India it is called "Saptaparna" and is regarded as the second sacred tree of Jainism.
The blackboard tree is a very unique plant, and its triangular trunk is particularly eye-catching in areas such as New Guinea.
Tree characteristics
The blackboard tree can grow up to 40 meters (130 feet) tall. The mature bark is gray and the young branches are covered with stomata. The leaves are smooth on the upper surface and gray below, and usually grow in rings of three to ten leaves. The leaves are narrowly oval to narrowly spatulate in shape, wedge-shaped at the base and usually rounded at the top, up to 23 cm (9.1 in) long and 8 cm (3.1 in) wide. Its flowers bloom in October and have a strong fragrance, similar to those of tuberose.
Distribution range
The blackboard tree has a wide range of adaptations, covering China, the Indian subcontinent (such as Bangladesh, India, Nepal, Pakistan and Sri Lanka), and Southeast Asia (such as Cambodia, Laos, Indonesia, Malaysia, Myanmar, Philippines, Thailand and Vietnam) and Oceania (such as Papua New Guinea and Queensland, Australia). In India, the blackboard tree is designated as the state tree of West Bengal and is known locally as the "Chhatim tree".
Toxic effects
Although the blackboard tree is widely used in traditional medicine, it is actually a poisonous plant. High doses of plant extracts have shown signs of causing significant organ damage in experiments on rats and mice. According to the study, toxicity is related to the plant part studied, and the season of harvest is also an important factor: bark collected during the monsoon season is the least toxic, while bark collected in the summer is the most toxic. The toxicity of intraperitoneal administration is significantly higher than that of oral administration.
The toxicity may be related to the alkaloid "Echitamine" in the bark, which was detected in all samples and is commercialized as an herbal medicine.
Chemical composition
The bark of the blackboard tree contains several alkaloids, including solanine, Echitamine, etc. Among them, Echitamine is the most important and is considered to have commercial value. The presence of these compounds has made the blackboard tree of widespread interest in the medical community, but has also highlighted its potential toxicity.
Purpose
The wood of the blackboard tree is recommended for making pencils because of its suitability, rapid growth, and ease of cultivation. In Sri Lanka, its light wood was used to make coffins. And in Borneo, the wood from its roots is used as fishing net buoys and household utensils. In ancient Buddhist legends, the first Buddha is said to have attained enlightenment under the blackboard tree. This shows the importance of this tree in culture.
In India, the leaves of the blackboard tree are given to graduates at graduation ceremonies. This is a cultural tradition started by Rabindranath Tagore and symbolizes the journey of learning and acquiring knowledge.
Although the blackboard tree is widely used in traditional medicine and was once thought to have an impact on malaria, final experimental results showed that it has little effect on the pathogen that causes diarrhea. This duality in the plant world has aroused more attention and thinking: How should we treat plants in nature that are both curative and toxic?
