Overview of Oncoba lasiocalyx Oliv.
Oncoba lasiocalyx Oliv. is a deciduous shrub that belongs to the Salicaceae family. It is commonly known as "fried egg plant" or "satinwood" due to the appearance of its fragrant flowers and the satin-like texture of its wood.
Origin and Distribution
Oncoba lasiocalyx Oliv. is native to Western and Central Africa, specifically Cameroon, Congo, Gabon, and Nigeria. It grows well in tropical and subtropical regions, where there is sufficient rainfall and sunlight. This species can also be found in other parts of the world like South America, Southeast Asia, and the Caribbean.
General Appearance
The Oncoba lasiocalyx Oliv. plant has a height of 2 to 8 meters and a spread of up to 5 meters. It has a rounded and bushy shape, with a dense crown and greyish-brown bark. The leaves are elliptical or lance-shaped, about 10 to 30 centimeters long, and have a glossy dark green color. The fragrant flowers are creamy-white with yellow stamens and a diameter of about 5 centimeters. The fruits are yellowish-brown capsules that split open to release small brownish-black seeds.
Uses
The Oncoba lasiocalyx Oliv. plant is widely used in African traditional medicine to treat various ailments like fever, cough, and stomachache. The bark, leaves, and roots contain compounds like alkaloids, flavonoids, and tannins, which have antimicrobial and antifungal properties. The wood of this plant is highly valued for making furniture, flooring, and decorative objects due to its durability and beautiful satin-like texture. The fruits are also edible and can be eaten fresh or used to make jams and jellies.
Light Requirements
Oncoba lasiocalyx Oliv. generally prefers full to partial sunlight exposure. However, during the young seedling stage, it is recommended to provide shaded conditions to avoid damage from direct sunlight. This plant species thrives well in bright, indirect, or filtered light as this will promote healthy growth.
Temperature Requirements
The optimal temperature range for the growth and development of Oncoba lasiocalyx Oliv. is between 20°C to 27°C. The plant can tolerate higher temperatures up to 30°C, but prolonged periods of high temperatures can negatively impact growth. In contrast, temperatures below 10°C can lead to slow growth, leaf fall, and ultimately, death of the plant.
Soil Requirements
Oncoba lasiocalyx Oliv. prefers well-draining, loamy soils with a pH range of 6.0 to 7.5. In their natural habitat, they grow near riverbanks, which implies that the plant thrives in soils that are rich in organic matter and hold sufficient moisture. Therefore, it is recommended to add organic material to the soil of plants grown in areas with low fertility. Additionally, the roots of this species can become root-bound; hence, repotting should occur every two to three years.
Cultivation Methods
Oncoba lasiocalyx Oliv. is typically grown from seed. The seeds should be planted in a well-draining soil mixture and kept moist until they germinate. It's recommended that the mature plant be grown in full sun or partial shade with some protection from high winds.
Watering Needs
It's important to keep the soil consistently moist but not waterlogged as Oncoba lasiocalyx Oliv. does not tolerate drought well. During the growing season, it's recommended to water the plant regularly, about once a week. However, during the dormant period, the soil should be allowed to dry out more between watering sessions.
Fertilization
Oncoba lasiocalyx Oliv. benefits from regular fertilization during the growing season. A balanced, slow-release fertilizer should be applied at the base of the plant. Additionally, regular applications of compost or well-rotted manure can help improve the overall health and productivity of the plant.
Pruning
Oncoba lasiocalyx Oliv. benefits from occasional pruning to promote healthy growth and a more attractive shape. Pruning should be done during the dormant season when the plant is not actively growing. It's recommended to remove any dead, diseased, or damaged branches. Additionally, pruning can help to control the size and shape of the plant.
Propagation of Oncoba lasiocalyx Oliv.
Oncoba lasiocalyx Oliv., commonly known as the Rambling yellowwood or sabi star, is a plant species from Southern Africa. It belongs to the Bignoniaceae family and produces attractive yellow flowers that can bloom all year round. Propagation of this plant can be done through two main methods - seed propagation and vegetative propagation.
Seed propagation
Propagation of Oncoba lasiocalyx Oliv. from seed is relatively easy but requires patience as it takes time for the seedlings to establish. Follow these steps to propagate the plant from seeds:
- Collect ripe fruits from the plant and extract the seeds.
- Clean the seeds and let them dry for a few days to prevent mold growth.
- Sow the seeds in a well-draining potting mix and cover them with a thin layer of soil.
- Water the seeds gently and place them in a warm location with bright, indirect light.
- Keep the soil moist but not waterlogged, and the seeds will germinate within 2-4 weeks.
Vegetative propagation
Vegetative propagation of Oncoba lasiocalyx Oliv. is done using stem cuttings or layering. Follow these steps to propagate the plant vegetatively:
- Select a healthy stem that is free from any diseases or pests.
- Cut a 10-15 cm stem, making sure to take a section that has at least two nodes.
- Remove the leaves from the bottom half of the stem, leaving only a few at the top.
- Dip the cut end of the stem in rooting hormone powder.
- Plant the cutting in a well-draining potting mix and water it thoroughly.
- Cover the pot with a plastic bag or glass jar to maintain humidity and place it in a bright, shaded location.
- After a few weeks, the cutting will start rooting, and you can remove the covering gradually.
Layering involves bending a low-hanging stem to the ground and covering it with soil to allow the plant to produce roots at the buried nodes. After a few weeks, the stem can be cut from the mother plant and potted separately.
Disease Management
Oncoba lasiocalyx Oliv. is susceptible to various fungal and bacterial diseases. The most common ones are leaf spots, stem and root rots, and powdery mildew. The disease symptoms usually start as small spots on the leaves, which gradually enlarge and cause the foliage to wilt and die. To manage these diseases, it is essential to follow good cultural practices such as;
- Pruning and removing infected plant parts
- Avoiding overhead watering, especially during high humidity
- Planting in well-draining soil and ensuring good air circulation
- Applying fungicides and bactericides at the first signs of infection
Pest Management
Oncoba lasiocalyx Oliv. is also vulnerable to several pests, including mealybugs, aphids, and caterpillars. These pests feed on the plant sap, causing the leaves to curl and distort. Proper pest management practices include:
- Regularly inspecting the plants for signs of infestation
- Handpicking and removing the pests as soon as they are detected
- Applying insecticidal soap or horticultural oil to control the pests
- Introducing natural enemies such as ladybugs and lacewings to control the pest populations
By following good practices for disease and pest management, Oncoba lasiocalyx Oliv. can thrive and produce healthy growth. Regular monitoring of the plant's health and early intervention are crucial to prevent the spread of diseases and pests.
