Origin
Strophanthus sarmentosus DC. var. sarmentosus is a plant species that is indigenous to tropical and subtropical regions of Africa, including Cameroon, Gabon, Nigeria, and the Congo Basin. It belongs to the family Apocynaceae and is a member of the genus Strophanthus.
Common Names
This plant species is known by a few common names in various regions it is found. In Cameroon, it is called "Ngansok", while in Nigeria, it is referred to as "Ochu". In Gabon, it is known as "Nsoso", and in the Congo Basin, it is called "Lepi".
Uses
Strophanthus sarmentosus DC. var. sarmentosus has various medicinal uses in its indigenous regions. It has been traditionally used as an anti-poison, diuretic, and purgative agent. Infusions of the plant are commonly used in the treatment of snake bites, scorpion stings, and various other poisons. It is also used as a remedy for treating asthma, ulcers, and gonorrhea. The plant contains cardiac glycosides, which are used in modern medicine to produce digitalis, a drug used to treat heart diseases.
General Appearance
Strophanthus sarmentosus DC. var. sarmentosus is a climbing shrub that can grow up to 15 meters tall. The plant has a woody stem, which is covered in numerous yellowish-grey spines. The leaves are simple, opposite, and ovate in shape, with a length of about 4-8 cm. The plant produces white or cream-colored flowers, which are funnel-shaped and about 2-4 cm long. The flowers have a strong fragrance and produce slender, black, and elongated fruits that contain numerous seeds.
Growth Conditions for Strophanthus sarmentosus DC. var. sarmentosus
Light: Strophanthus sarmentosus DC. var. sarmentosus grows well in bright indirect light to partial shade. It is not advisable to place it under direct sunlight for extended periods as it can scorch and damage the leaves.
Temperature: The plant thrives in a warm and humid environment. The ideal temperature range is between 20 and 30°C. It cannot withstand frost or extreme cold temperatures and may die if exposed to such conditions.
Soil: A well-draining soil mix that is rich in organic matter is best for the Strophanthus sarmentosus DC. var. sarmentosus. A mixture of peat moss, perlite, and coarse sand in a ratio of 2:1:1 provides the best drainage and aeration. The soil should have a pH range of 6.0 to 7.5.
Water: The Strophanthus sarmentosus DC. var. sarmentosus prefers soil that is evenly moist but not waterlogged. Overwatering can lead to root rot, which can be fatal to the plant. Water the plant thoroughly and allow the top inch of soil to dry before watering again. During the winter season, reduce watering frequency.
Fertilizer: The plant benefits from regular fertilization during the growing season (spring, summer, and early fall). A balanced fertilizer with an NPK (nitrogen, phosphorus, and potassium) ratio of 10-10-10 works well. Reduce fertilizer application during the winter season.
Humidity: The Strophanthus sarmentosus DC. var. sarmentosus requires a high level of humidity to thrive. You can maintain humidity by placing the plant on a pebble tray that is filled with water. Alternatively, you can use a humidifier or mist the plant regularly.
Propagation: The plant can be propagated through stem cuttings taken during the growing season. Ensure that the cuttings have at least two nodes and place them in a well-draining soil mix. Provide warm and humid conditions until roots develop, and the plant starts growing.
Cultivation Methods of Strophanthus sarmentosus DC. var. sarmentosus
Strophanthus sarmentosus DC. var. sarmentosus is a moderately easy plant to cultivate. It grows well in warm and humid conditions with moist soil. It can grow well in direct sunlight as well as partial shade. The plant can be propagated through seeds or cuttings.
Watering Needs of Strophanthus sarmentosus DC. var. sarmentosus
Strophanthus sarmentosus DC. var. sarmentosus needs to be watered regularly to keep the soil moist. However, it is important not to overwater the plant as it can lead to root rot or fungus growth. The frequency of watering should be reduced in winter or during a drought when the soil remains moist for a longer duration.
Fertilization of Strophanthus sarmentosus DC. var. sarmentosus
Strophanthus sarmentosus DC. var. sarmentosus requires regular fertilization for healthy growth. Organic fertilizers like compost or well-rotted manure help in providing the required nutrients to the plant. Slow-release fertilizers can also be used to promote continuous growth. Fertilizing the plant once every two weeks during the growing season can be ideal.
Pruning of Strophanthus sarmentosus DC. var. sarmentosus
Pruning Strophanthus sarmentosus DC. var. sarmentosus is not necessary, but it can promote branching and healthy growth. Pruning is recommended in spring or after the blooming season. Cut off any damaged or diseased stems or branches. The plant can also be shaped to keep it compact and tidy.
Propagation of Strophanthus sarmentosus DC. var. sarmentosus
Strophanthus sarmentosus DC. var. sarmentosus can be propagated through both vegetative and sexual methods. The choice of method should be based on the availability, time, and resources, and the desired outcome.
Vegetative propagation
Vegetative propagation of Strophanthus sarmentosus DC. var. sarmentosus can be achieved primarily through stem cuttings. Cuttings should be taken from healthy and disease-free plants in early spring or late summer. The cutting should be 5-8 cm long, and the leaves and flowers should be removed. The cutting should be dipped into rooting hormone powder, then planted in sterilized soil in a pot. The pot should be placed in a warm, humid, and shaded place and kept moist until the roots develop.
Sexual propagation
Sexual propagation of Strophanthus sarmentosus DC. var. sarmentosus requires collecting seeds from a mature and healthy plant. The seeds should be harvested when mature and plump, and the seed pods must be dry and crispy. The seed pods should be cut open, and the seeds should be collected. The seeds should be sown in sterilized soil in a pot or seed tray, and lightly covered with soil. The pot or tray should be placed in a warm and humid place with partial shade and kept moist until the seeds germinate.
Disease and Pest Management for Strophanthus Sarmentosus DC. var. Sarmentosus
Strophanthus sarmentosus DC. var. sarmentosus is a hardy plant that can resist pests and diseases; however, it can still be affected by several insects and pathogens. Here are some of the common diseases and pests that might affect the plant and ways to manage them:
Diseases
Anthracnose: Anthracnose is a fungal disease that can cause dark lesions on the plant's leaves, stems, and fruits. The affected parts will eventually wither and die. To manage anthracnose, you can apply fungicides, maintain good sanitation practices, and remove infected parts of the plant.
Leaf spot: Leaf spot is another fungal disease that causes brown spots on the plant's leaves. The spots can merge and cause the leaves to fall off prematurely. To manage leaf spot, you can apply fungicides, avoid overhead watering, and remove infected leaves and plants debris.
Root rot: Root rot is a fungal disease that affects the plant's roots, causing them to rot and die. To manage root rot, you can improve soil drainage and avoid overwatering.
Pests
Aphids: Aphids are small insects that suck the plant's sap, causing stunted growth and distorted leaves. You can manage aphids by spraying the plant with soapy water, applying neem oil, or introducing natural predators such as ladybugs.
Spider mites: Spider mites are tiny arachnids that feed on the plant's sap, causing yellow leaves with tiny spots. To manage spider mites, you can spray the plant with water to create a humid environment, apply insecticidal soap, or introduce natural predators such as predatory mites.
Caterpillars: Caterpillars are the larval stage of moths and butterflies, and they can chew on the plant's leaves, causing defoliation. To manage caterpillars, you can pick them off by hand, apply Bacillus thuringiensis (Bt), or introduce natural predators such as birds.
By practicing good sanitation, proper watering, and timely application of pesticides, you can manage the common diseases and pests that may affect Strophanthus sarmentosus DC. var. sarmentosus and keep the plant healthy and productive.
