Origin and Common Names
Antiaris toxicaria Lesch. var. welwitschii, commonly known as the sapwood tree or upas tree, is a species of flowering plant in the mulberry family Moraceae. It is native to tropical Africa, including Angola, Cameroon, Central African Republic, Congo, Gabon, Ghana, Ivory Coast, Nigeria, and Sierra Leone.Appearance
The sapwood tree can grow up to 40 meters tall, with a trunk that can be over 1 meter in diameter. It has a straight, cylindrical stem with a rounded top, and its bark is dark brown and rough. The leaves are simple, alternate, and ovate, about 17 centimeters long and 11 centimeters wide, and have a pointed tip and a rounded base. The tree is dioecious, with male and female flowers on separate trees. The male flowers are spiky and yellow, while the female flowers are round and green.Uses
The sapwood tree has a long history of use in traditional medicine and as a source of timber. Some tribes in Cameroon and Congo use the plant extract to treat a variety of conditions, including malaria, constipation, and respiratory diseases. The sap from the tree is also used as a poison, particularly among African hunters, to kill large mammals such as elephants and hippos. The timber from the sapwood tree is hard, heavy, and durable, making it useful for construction, furniture, and boat-building. However, due to its toxic properties, the sapwood tree is rarely planted outside of its native range and is not commonly used in international commerce.Light Requirements
The Antiaris toxicaria Lesch. var. welwitschii thrives in partially shaded conditions. The plant prefers to receive dappled sunlight or indirect morning/evening light and should avoid harsh afternoon sunlight as it may damage the leaves.
Temperature Requirements
The plant grows best in tropical and subtropical climates with an average temperature of 20-30°C (68-86°F). Extreme temperatures, either hot or cold, can harm the plant, and it is sensitive to frost.
Soil Requirements
The Antiaris toxicaria Lesch. var. welwitschii prefers well-draining soil that retains moisture and offers adequate aeration for the roots. The soil should be rich in nutrients, slightly acidic, and have a pH range between 5.5 and 6.5. A mix of peat moss and perlite can make an excellent potting medium.
Cultivation Methods
Antiaris toxicaria Lesch. var. welwitschii is primarily found in tropical rainforests. The plant thrives in warm and humid environments with a temperature range of 20-30°C. When cultivating, ensure that the plant is provided with a well-draining soil mix. Choose a shaded, sheltered area with partial to full sunlight depending on the intensity of sunlight in your region. An ideal soil mix for cultivation would include materials such as coconut coir, sphagnum moss, and sand.
Watering Needs
Proper watering for Antiaris toxicaria Lesch. var. welwitschii is critical for its growth. The plant should always have moist soil, but take caution not to over-water as this may cause root decay. A watering schedule of twice a week is ideal, but ensure that you check the soil moisture level regularly and adjust accordingly.
Fertilization
To boost growth and ensure proper development of Antiaris toxicaria Lesch. var. welwitschii, frequent and appropriate fertilizing is necessary. Use high-quality fertilizers that are balanced, rich in nitrogen, phosphorus, and potassium. Fertilize the plant once every two months for the best results.
Pruning
Regular pruning is necessary for Antiaris toxicaria Lesch. var. welwitschii to establish a desirable shape and density. Use pruning shears to remove dead, damaged, or diseased plant parts as soon as you notice them. Pruning also improves air circulation, thus reducing the likelihood of disease and pests.
Propagation of Antiaris toxicaria Lesch. var. welwitschii
Antiaris toxicaria Lesch. var. welwitschii is commonly known as the upas tree. It is a native to tropical areas like Africa, Madagascar, and India. The tree possesses a toxic sap that contains cardiac glycosides and alkaloids. Propagation of the plant can be done vegetatively or from seeds. Here are the different propagation methods for Antiaris toxicaria Lesch. var. welwitschii:
Propagation by Seeds:
Propagation of Antiaris toxicaria Lesch. var. welwitschii can be done by seeds. To harvest the seeds, collect its fruits from the tree's canopy before they fall to the ground. Separate the seeds from the pulp and clean them. Use a well-drained soil mix for sowing, and cover the seeds with a thin layer of soil. Water the soil lightly and cover it to maintain optimal moisture levels. Seeds start germinating within 2-3 weeks, and seedlings can be transferred to the planting site after two to four months.
Vegetative Propagation:
Antiaris toxicaria Lesch. var. welwitschii can also be propagated by vegetative means. This method involves the use of cuttings from the tree's matured wood. Select a branch with matured wood and cut it into sections of 15-20 cm. Soak the cuttings in a rooting hormone before plantation. The cuttings start to root within six to eight weeks approximately. Transplant the rooted cuttings in pots or other sites to be grown and matured into trees.
Air Layering:
Air layering is another means of propagating Antiaris toxicaria Lesch. var. welwitschii. This is done by selecting a branch and removing the bark from a section of 15-20 cm. Apply a rooting hormone to the exposed wood area and cover it with moist sphagnum moss. Wrap a plastic sheet around the moss to maintain the moisture level and prevent it from drying. After three to four months, roots develop and can be cut from the tree for planting.
Propagation of Antiaris toxicaria Lesch. var. welwitschii by seed, cutting, or air layering is relatively straightforward and could be done by anyone who has experience with tropical tree species. Regardless of the method chosen, the plant must be adequately tended to until they grow into massive trees that can reside up to over 20 meters tall.
Disease Management
Antiaris toxicaria Lesch. var. welwitschii is susceptible to various fungal and bacterial diseases which can cause significant damage to the plant. Here are some of the common diseases and their management:
Fungal Diseases:
Anthracnose: This disease is caused by several species of fungi, and it affects the leaves, fruits, and stems of the plant. The symptoms are dead spots, sunken areas on leaves, and the blackening of stems. To manage anthracnose, you need to prune and destroy the affected parts of the plant, and apply fungicides.
Phytophthora and Pythium root rot: These are soil-borne diseases that attack the roots. The symptoms are stunted growth, wilting leaves, and root rotting. To manage these diseases, you need to avoid over-watering the plant, well-draining the soil, and applying fungicides.
Bacterial Diseases:
Bacterial leaf spot: This disease results in black spots appearing on the leaves, and it is caused by Xanthomonas campestris. To manage bacterial leaf spot, you must remove the affected leaves, avoid water splashing, and apply copper-based fungicides.
Pest Management
Antiaris toxicaria Lesch. var. welwitschii is also vulnerable to insect and pest attacks. Common pests that can affect the plant include:
Mealybugs:
These sap-sucking insects cause yellowing leaves, wilting, and stunted growth. To manage mealybugs, you need to remove the affected parts of the plant, spray with insecticidal soap, and introduce natural predators such as ladybugs and lacewings.
Scale Insects:
These pests attach themselves to the stems of the plant and feed on the sap. They cause yellowing, wilting, and stunted growth. To manage scale insects, prune and destroy the affected parts of the plant, apply insecticidal soap, and introduce natural predators such as ladybugs and lacewings.
Aphids:
These insects also feed on the sap of the plant, resulting in wilting leaves and stunted growth. To manage aphids, you need to wash off the insects with a strong spray of water, apply insecticidal soap, and introduce natural predators such as ladybugs and lacewings.
Regular inspection of the plant is essential in managing diseases and pests. Early detection and treatment can significantly reduce the spread and damage to the plant.
