Plant Description:
Picralima umbellata, also known as the African cherry, is a plant species native to tropical Africa. It belongs to the family Apocynaceae and is a small to medium-sized tree that grows up to 25 meters tall. The tree produces a bitter, yellow latex that has medicinal properties.
Common Names:
The plant is known by a variety of common names in different parts of Africa, including akuamma, vincamajoridine, and ayo. Its common name, African cherry, refers to the shape and color of its small cherry-like fruits that grow in clusters.
Uses:
The seeds of Picralima umbellata are a valuable source of alkaloids, including akuammine, which has analgesic properties. The seeds are traditionally used in parts of West Africa to treat pain, fever, and diarrhea. They are also used as a natural remedy for malaria and as a stimulant.
The bark of the tree has been used to treat coughs, bronchitis, and stomach ailments. The yellow latex produced by the tree is used to treat skin infections, and the leaves have been used to make a poultice to reduce swelling and inflammation.
General Appearance:
The Picralima umbellata tree has a straight trunk with gray-brown bark that has a rough appearance. Its leaves are dark green and shiny, with a length of up to 25 centimeters. The tree produces small, greenish-yellow flowers that grow in clusters and are followed by cherry-sized fruits. The fruit's pulp is edible but not commonly consumed, with seeds that are collected for their medicinal properties.
Light Requirements
Picralima umbellata thrives in areas with bright, indirect light. Direct sunlight can scorch the leaves and stunt growth. The plant can adapt to low light conditions but will grow slower and produce smaller leaves.
Temperature Requirements
Optimal temperature for Picralima umbellata growth is between 20-25°C. The plant can tolerate higher temperatures up to 30°C but growth may slow down. Temperatures below 15°C can cause growth to stall, and the plant may eventually die. This makes the plant suitable for growth in tropical and subtropical regions.
Soil Requirements
Picralima umbellata requires well-draining soil with a slightly acidic to neutral pH between 5 and 7. The soil mix should contain a good amount of organic matter and be rich in nutrients. A mixture of loamy soil and compost provides the suitable medium for growth. It's important to ensure that the soil does not get waterlogged as this can lead to root rot and eventually death of the plant.
Cultivation Methods
Picralima umbellata is a tropical plant native to Africa. It is commonly grown for its medicinal properties, and is also a popular ornamental plant. The plant thrives in warm, humid environments and prefers well-drained soil. It can be grown in containers or in the ground.
To start cultivation, select a location that receives partial shade to full sun. Dig a hole twice the size of the plant's root ball. Mix the soil with compost or organic fertilizer to improve drainage and nutrient content. Place the plant in the hole and backfill the soil, firming it down gently.
Watering Needs
Regular watering is important for the growth and survival of Picralima umbellata. Water deeply and regularly during the growing season. Allow the soil to dry slightly between watering to avoid over-watering, but do not let the soil dry completely.
During the winter months, reduce watering frequency. Too much water can lead to root rot, which is a common problem for this plant. If the leaves begin to wilt or turn yellow, it is a sign of over-watering.
Fertilization
Fertilize Picralima umbellata during the growing season with a balanced fertilizer. Apply every two to three weeks, or according to the instructions on the fertilizer package. Over-fertilizing can cause the plant to produce fewer flowers or no flowers at all.
Avoid fertilizing in the winter, when the plant is dormant. Fertilizing during this time can cause the plant to produce weak or spindly growth.
Pruning
Pruning is not necessary for the growth and health of Picralima umbellata. However, pruning can help to shape the plant and remove dead or diseased branches.
Prune the plant in the spring, just before the growing season begins. Use clean, sharp pruning shears to make clean cuts. Avoid pruning during the winter, when the plant is dormant.
Remove dead or diseased branches as soon as they appear to prevent the spread of disease. Remove any crossing branches or branches that are rubbing against each other to prevent damage and improve air circulation.
Propagation of Picralima umbellata (K.Schum.) Stapf
Picralima umbellata (K.Schum.) Stapf can be propagated through various methods, including seed propagation, stem cuttings, and root cuttings. Each of these methods has its own advantages and disadvantages, and the choice of method may depend on the resources available and the desired outcome.
Seed Propagation
The most common method of propagating Picralima umbellata is through seed propagation. Seeds are readily available from mature plants, which can be collected during the fruiting season. The seeds should be cleaned and sown in seedling trays filled with a well-draining soil mix. The ideal soil pH range is between 6.5 and 7.5. The trays should be covered with a clear plastic cover to maintain moisture and placed in a warm, bright location, but out of direct sunlight. Germination usually occurs within two to three weeks, and the seedlings should be transplanted into individual pots when they are large enough to handle.
Stem Cuttings
Stem cuttings can also be used to propagate Picralima umbellata. Cuttings should be taken from a healthy, mature plant and should be around 10-15 cm long. Remove the lower leaves and dip the cut end in rooting hormone powder to encourage root growth. Place the cutting in a well-draining soil mix and cover with a clear plastic bag to maintain humidity. After 2-3 weeks, roots should start to develop, and the cutting can be transplanted to a larger pot with a well-draining soil mix.
Root Cuttings
Root cuttings can be used to propagate Picralima umbellata, but this method is less commonly used. The plant's roots should be dug up during the dormant season, and sections of the roots should be cut into 2-3 cm pieces. These root cuttings should be potted in soil mix, and kept warm and moist. It takes longer for root cuttings to propagate than other methods, so it is advised to have patience.
It is essential to maintain moisture and provide proper light to the propagating Picralima umbellata. The new plants require more care than established plants. Therefore it is important to put the newly propagated plants in well-draining soil and keep them warm and moist until they are established.
Disease Management
Picralima umbellata is susceptible to several fungal and bacterial diseases that can cause a significant reduction in plant health and yield. The most common diseases that affect this plant include leaf spots, powdery mildew, and root rot.
To manage leaf spots, it is advisable to practice good sanitation, remove infected leaves, and avoid overhead watering. Additionally, fungicides such as copper-based products and chlorothalonil can be used to control the spread of the disease.
Powdery mildew can be controlled by reducing humidity levels around the plant and increasing air circulation. Fungicides such as sulfur and potassium bicarbonate can also be used as a preventive measure to reduce the severity of the disease.
Root rot can be a severe issue for P. umbellata as it can lead to stunted growth, wilting of leaves, and death. To manage root rot, proper soil drainage is essential, and the use of fungicides such as mefenoxam and metalaxyl can be used to control the spread of the disease.
Pest Management
Pests can also pose a significant threat to the health and yield of P. umbellata. The most common pests that affect this plant include mites, aphids, and mealybugs.
Mites can cause severe damage to the plant's foliage, leading to defoliation. To manage mites, it is essential to increase humidity levels around the plant and avoid using pesticides that may harm natural predators such as ladybirds.
Aphids can cause stunted growth, yellowing leaves, and the development of sooty mold. To manage aphids, it is advisable to introduce natural predators such as ladybirds and lacewings. Additionally, insecticidal soaps and neem oil can be used as a preventive measure to reduce the severity of the infestation.
Mealybugs can cause wilting and yellowing of leaves and sticky sap exudation on the plant's surface. To manage mealybugs, it is advisable to remove infected plant parts, and the use of insecticidal soaps and neem oil can be used to control the infestation.
