Overview
Cynanchum welwitschii Schltr. & Rendle is a species of flowering plant in the family Apocynaceae native to Angola. It is commonly known as "Amhara arrow poison," as it is traditionally used by the Amhara people in Ethiopia for hunting and defense.
Description
Cynanchum welwitschii Schltr. & Rendle is a perennial herb or woody climber with a milky sap that is toxic to animals and insects. The plant can grow up to 6 meters in length, with stem diameter ranging from 1 to 4 cm. The leaves are opposite, elliptic, and measure up to 10 cm long and 5 cm wide. The flowers are small and greenish-yellow, measuring up to 6 mm in diameter, and are arranged in clusters at the end of the stem.
Uses
Traditionally, Cynanchum welwitschii Schltr. & Rendle has been used by the Amhara people in Ethiopia as a poison for hunting and defense. The milky sap of the plant is extracted and applied to arrows or spears to immobilize or kill prey. The plant's toxic properties have also been explored for potential use as a pesticide.
In modern medicine, Cynanchum welwitschii Schltr. & Rendle has been investigated for its potential anti-cancer properties. Research has shown that the plant's milky sap contains compounds that can inhibit the growth of cancer cells, although further research is needed to explore its potential use as a cancer treatment.
Cynanchum welwitschii Schltr. & Rendle is not recommended for consumption or medicinal use without proper preparation and medical supervision due to its toxic properties.
Light Requirements
Cynanchum welwitschii Schltr. & Rendle is a plant that requires full sunlight to grow properly. It can tolerate partial shade, but continuous exposure to the sun is essential for the plant's development. With adequate sunlight, the plant can produce more flowers and fruits, leading to healthy and robust plant growth.
Temperature Needs
The plant grows well in warm to hot environments. It thrives in temperatures ranging from 15°C to 35°C. The plant can withstand high temperatures as long as it gets enough water. The minimum temperature requirement for the plant is 10°C. If the temperature drops below this limit, the plant's growth stops, and its leaves start to fall off.
Soil Requirements
Cynanchum welwitschii Schltr. & Rendle prefers well-drained soils with a pH range between 5.5 and 7.5. The soil should be rich in organic matter and nutrients. The plant can grow in different soil types, such as sandy and loamy soils. However, the plant requires moderate to high soil moisture to grow well. The soil should also be free from any obstacles that may hinder root development.
Cultivation Methods
Cynanchum welwitschii Schltr. & Rendle is a rare and endangered plant species found in the tropical regions of Africa. To cultivate this plant, one needs to mimic its natural environment. The plant prefers well-drained and nutrient-rich soil with a pH range of 6 to 8. The location should have abundant sunlight and protection from harsh winds. Propagation is either by seed or cuttings.
Watering Needs
This plant requires moderate watering. Over-watering can lead to root rot, and under-watering makes the plant vulnerable to drought. During the growing season, ensure the soil is evenly moist, but allow the soil to dry slightly before the next watering session. In winter, reduce watering to prevent waterlogging that can cause damage to the roots.
Fertilization
To promote healthy growth, add organic fertilizer to the soil during the growing season. Use nitrogen-rich fertilizers to boost leafy growth. Avoid excessive use of synthetic fertilizers as they can harm the plant's roots and negatively affect the soil quality. Follow the instructions on the fertilizer package, as too much fertilizer can lead to salt buildup, stunting growth, and burning of leaves, among other problems.
Pruning
Cynanchum welwitschii Schltr. & Rendle is a woody climber plant that can grow up to 5 meters tall. During the growing season, regular pruning is essential to control its height and shape. Remove any dead or damaged branches to prevent pest infestation, and avoid over-crowding the plant. Prune right above the node to encourage new growth, and use clean and sharp pruning tools.
Propagation of Cynanchum welwitschii Schltr. & Rendle
Cynanchum welwitschii Schltr. & Rendle, commonly known as the Welwitsch's swallow-wort, can be propagated through both seeds and cuttings. However, seed propagation is the most commonly used and preferred method for propagating this plant.
Seed Propagation
The seeds of Cynanchum welwitschii Schltr. & Rendle should be sown in spring or early summer. To ensure successful germination, the seeds should be sown in well-draining soil and kept evenly moist. The ideal temperature range for germination is between 20°C and 25°C. Germination can take anywhere from 2 to 12 weeks.
Once the seedlings have grown to a height of about 5 cm, they can be transplanted into individual pots or directly into the ground. It is important to ensure that the soil is rich in nutrients and well-draining. The plants should be watered regularly until they become established.
Cutting Propagation
Cuttings can also be used to propagate Cynanchum welwitschii Schltr. & Rendle. The best time to take cuttings is in late spring or early summer. The cuttings should be taken from new growth and should be at least 7 cm in length.
The cuttings should be dipped in a rooting hormone and then planted in well-draining soil. The soil should be kept moist but not waterlogged. After a few weeks, the cuttings should start developing roots. Once the roots have formed, the cuttings can be transplanted into individual pots or directly into the ground.
It is important to protect young plants from direct sunlight and strong winds until they become established.
Disease Management
Cynanchum welwitschii Schltr. & Rendle is generally a hardy plant that is less susceptible to diseases. However, if proper care is not taken, it can be attacked by various diseases such as Leaf Spot, Powdery Mildew and Rust.
Leaf Spot: This disease is caused by a fungus and results in the appearance of tiny spots on plant leaves. To manage this disease, cut down the affected leaves and remove them from the area. Also, maintain proper spacing between the plants to allow air circulation and regular watering to maintain the moisture content.
Powdery Mildew: This disease is caused by a fungus that appears as a powdery white substance on leaves, stems, and flowers. To manage this disease, remove the infected parts of the plant and destroy them. One can also use fungicide sprays or neem oil to lessen the spread of mildew.
Rust: This disease causes tiny rust colored colored spots on leaves that gradually spread to the entire plant. To control rust, prune and destroy the infected parts and leaves. Spray the plant with a suitable fungicide to prevent the spread of rust to healthy plants.
Pest Management
Cynanchum welwitschii Schltr. & Rendle plant can also get attacked by several pests such as aphids, spider mites, and mealybugs, which can weaken the plant and eventually lead to its death if not controlled.
Aphids: These are small, pear-shaped insects that feed on plant sap and can cause stunted growth and deformed leaves. To manage this pest, one can handpick and destroy them or use insecticidal soap or neem oil.
Spider Mites: These are tiny pests that suck sap from the leaves, causing them to yellow and fall off. To control spider mites, spray the affected plant with water to wash away the mites and use insecticidal soap or neem oil.
Mealybugs: These pests are small white insects that cause yellowing and wilting of leaves, and they produce a sticky substance that serves as a breeding ground for molds. To manage Mealybugs, remove the infected plant parts. One can also apply insecticidal soap or neem oil to control the numbers of mealybugs.
To prevent both diseases and pests, maintain good plant hygiene, remove weeds around the plant, provide adequate nutrition, and ensure proper spacing between the plants.
