Overview
Strophanthus niger Blondel ex Pax, also known as Black Strophanthus, is a species of plant in the Apocynaceae family. It is native to West Africa and is widely distributed from Guinea to Congo and Angola.
Common names
Strophanthus niger has several common names, including Bitter Strophanthus, Poison Arrow Plant, and Ouabaio.
Appearance
The Black Strophanthus is a woody climber that can grow up to 10 meters long. It has shiny leaves that are ovate, leathery, and measure 3 to 6 inches in length. The plant produces fragrant, white or pink flowers with narrow, twisted petals and a yellow-green center. The fruit of the Black Strophanthus is a long, slender pod that contains numerous seeds.
Uses
The Black Strophanthus plant is widely used in traditional African medicine for its medicinal properties. The plant contains a cardiac glycoside called Ouabain, which is used to treat heart failure and certain types of arrhythmias. The seeds of the plant are used to make arrow poison, which is used by several African tribes for hunting and warfare. The plant is also used in the pharmaceutical industry to synthesize cardiotonic drugs.
Light Requirements
The Strophanthus niger Blondel ex Pax plant requires full sun to grow properly. It needs at least 6 hours of direct sunlight per day to thrive. Without proper sunlight, the plant's growth and flowering will be affected, and it may not survive for long.
Temperature Requirements
The plant grows best in warm to hot temperatures. The ideal daytime temperature range for the Strophanthus niger is between 22°C and 32°C. At night, the temperature should not fall below 13°C. Temperatures below 10°C can cause damage to the plant.
Soil Requirements
The Strophanthus niger prefers well-draining soil that is rich in organic matter. The soil should be slightly acidic with a pH range of 5.5-7.0. It thrives in sandy soil with good drainage. It's important to keep the soil moist but not waterlogged. Overwatering can lead to root rot, which can be fatal to the plant.
Fertilization
The Strophanthus niger requires a balanced fertilizer that provides equal amounts of nitrogen, phosphorus, and potassium. The fertilizer should be applied once every two weeks during the growing season. Over-fertilizing can lead to excessive leaf growth, at the expense of flowering.
Cultivation of Strophanthus Niger Blondel ex Pax
Strophanthus niger Blondel ex Pax, commonly known as the Black Strophanthus, is a vine that requires warm temperatures to thrive. It is a tropical plant that can be trained to climb on trellises or other support. It should be planted in loamy, well-drained soil with a pH value of 6.5 to 7.5. The soil must be rich in organic matter, and it should be situated in direct sunlight or partial shade.
Watering Needs for Strophanthus Niger Blondel ex Pax
The Black Strophanthus requires moderate watering, especially in the growing season. It should be watered when the soil dries out, and the amount of water should be sufficient to saturate the soil. It is important to avoid over-watering as it can lead to root rot and other fungal diseases. During the winter, watering should be reduced to once every two weeks.
Fertilization of Strophanthus Niger Blondel ex Pax
To ensure proper growth and development, the Black Strophanthus requires regular fertilization. A balanced fertilizer with a 10-10-10 or 12-12-12 NPK ratio is ideal. Fertilization should be done once every two weeks during the growing season, and it should be reduced to once a month during winter. Applying organic matter such as compost, manure, or worm castings can also help to improve soil fertility.
Pruning of Strophanthus Niger Blondel ex Pax
Pruning helps to promote healthy growth and the development of new flowers. Pruning of Black Strophanthus should be done during the winter when the plant is dormant. It involves cutting out the dead and damaged branches, as well as trimming the plant's size to keep it within manageable limits. The pruning process also helps in the removal of overcrowded branches, ensuring adequate air circulation throughout the plant and reducing the risk of pest and disease infestations.
Propagation of Strophanthus niger Blondel ex Pax
Strophanthus niger Blondel ex Pax is a perennial plant that belongs to the Apocynaceae family. It is commonly known as poison rope, black poison, or arrow poison vine. It is native to West Africa, but it is widely cultivated in other parts of the world for its medicinal purposes.
The plant is propagated through both sexual and asexual methods. Here are the different propagation methods:
Seed Propagation
The most common method of propagating Strophanthus niger is through seeds. After harvesting the mature seeds from the plant, you should remove the silky hairs surrounding them. You can then sow the seeds in individual pots, trays, or a seed bed. The seeds should be sown shallowly in well-draining soil. Germination of the seeds can take between two to four weeks, and you should keep the soil moist throughout the process.
Vegetative Propagation
Strophanthus niger can be propagated through vegetative cuttings. This method involves taking stem cuttings from a healthy plant during the growing season. It is best to take a cutting with a length of about 10 cm and a diameter of 0.5 cm. The cuttings should be dipped in a rooting hormone and placed in well-draining soil or water. In about a month, roots should appear, and the cutting can be transplanted to a bigger container.
Air Layering
Air layering is a propagation method that involves creating roots on a stem while it is still attached to the mother plant. You should choose a healthy, mature stem and make a cut that goes about halfway through the stem's thickness. Apply rooting hormone on the cut, wrap the area with wet sphagnum moss or peat, and cover it with plastic. After roots form, you can cut the stem and plant it in a well-draining soil mix.
Regardless of the propagation method used, the resulting Strophanthus niger seedlings or clones should be kept in a warm, humid environment with indirect sunlight until they are ready to be transplanted into their final growing location.
Disease and Pest Management for Strophanthus niger Blondel ex Pax
Strophanthus niger Blondel ex Pax, commonly known as black-stemmed strophanthus, is a tropical vine that is native to West and Central Africa. While this plant is generally healthy, it is still susceptible to certain diseases and pests that can negatively impact its growth and overall health.
Common Diseases
One of the most common diseases that affect Strophanthus niger is leaf spot. This is characterized by circular or oval-shaped spots on the leaves that can be brown or black in color. If not addressed promptly, this disease can lead to defoliation and reduced growth. To manage leaf spot, remove infected leaves and avoid overhead watering, which can spread the disease. Additionally, apply a fungicide to protect undamaged leaves and prevent the spread of the disease.
Root rot is another common disease that Strophanthus niger might be prone to. Excessive watering or poorly-draining soil can cause the plant's roots to become waterlogged, leading to root rot. To prevent this, ensure that the plant is not overwatered and that the soil is well-draining. If root rot does occur, remove the affected parts of the plant and repot it in fresh soil.
Common Pests
Strophanthus niger is also susceptible to pests like spider mites, thrips, and aphids. Spider mites are tiny pests that suck the sap from the plant's leaves, causing them to yellow and fall off. To manage spider mites, use a miticide that is safe for the plant and the surrounding environment. Thrips and aphids can also damage the leaves of Strophanthus niger. To control these pests, wash the leaves with a soapy solution or apply an insecticide that is labeled for use on ornamental plants.
Overall, proper watering, adequate lighting, and good sanitation practices can help prevent common diseases and pests from affecting Strophanthus niger. By monitoring the plant regularly for signs of damage and promptly addressing any issues that arise, you can keep your Strophanthus niger healthy and thriving.
