Overview
Rhus angolensis Engl. forma glabrescens R.Fern., commonly known as the African Sumac or African Poison Ivy, is a deciduous plant species that belongs to the Anacardiaceae family. It is native to the southern and eastern parts of Africa, where it grows in savannah, woodland, and karoo habitats. This plant is widely recognized for its diverse medicinal and cultural uses.
General Appearance
This plant species is a medium-sized tree or shrub that can grow up to 12 meters tall. The bark is greyish-brown and rough, with small, irregular fissures. The leaves are compound, with an uneven number of leaflets that are lance-shaped and around 2-5cm long. The leaf edges are serrated.
The flowers, which bloom from August to December, are small and yellow to green in color. They grow in compact clusters at the ends of the branches. The fruit is a flat, papery, ovoid drupe that is around 1cm in diameter and turns red when ripe.
Common Names
This plant species has several common names across Africa, including African Sumac, African Poison Ivy, Rhus, Kuni, Umdoni, and Ushane. It is also known as umKhulu or umNsimbiti in Zulu.
Uses
Rhus angolensis Engl. forma glabrescens R.Fern. has several cultural and medicinal uses due to its tannin-rich bark and leaves. Historically, the bark and roots have been used to make astringent, tonic, and antidiabetic remedies. The bark and leaves also contain antioxidants, which are thought to have health benefits.
The tree is often used for shade, ornamental, and fuelwood purposes, as well as for soil stabilization. In South Africa, the leaves and bark of Rhus angolensis are used to tan leather. In Malawi, the plant is used as a pesticide to control insects and pests, and the roots are brewed into a tea to treat fever and flu-like symptoms.
Typical growth conditions for Rhus angolensis Engl. forma glabrescens R.Fern.
Rhus angolensis Engl. forma glabrescens R.Fern. is a deciduous tree that is native to Africa and prefers warm tropical climates. It grows best in areas with an average annual rainfall of 500-1000 mm and temperatures ranging from 20-35°C. The tree is tolerant of drought, making it well-suited to arid regions.
Light requirements
The tree prefers full sun but can also grow in partial shade. In areas with high temperatures, it is advisable to provide some shade to prevent sunburn.
Temperature requirements
Rhus angolensis Engl. forma glabrescens R.Fern. is a warm tropical tree and does not tolerate frost. Temperatures below 0°C can kill the tree. The ideal temperature range for the tree is 20-35°C. It can withstand extreme temperatures, making it an excellent choice for areas with high temperature fluctuations.
Soil requirements
The tree is adaptable to a range of soil types, including sandy, loamy, and clay soils. However, it prefers well-draining soils with a pH between 6-7.5. The tree can grow in soil with low nutrient content but performs best in fertile soils with added organic matter.
Cultivation of Rhus angolensis Engl. forma glabrescens R.Fern.
Rhus angolensis Engl. forma glabrescens R.Fern. is a shrub species that can grow between 2 and 5 meters tall. It is best grown in well-draining soil with a pH range of 6 to 7. For optimum growth, it is recommended to plant in an area with partial shade or filtered sunlight, avoiding areas with direct sunlight.
Watering Needs
Newly planted Rhus angolensis Engl. forma glabrescens R.Fern. should be watered frequently to allow for root establishment. Mature plants require watering only once a week during the dry season, and less frequently during the rainy season. It is important to ensure that the soil is not waterlogged as this can lead to root rot.
Fertilization
Rhus angolensis Engl. forma glabrescens R.Fern. benefit from regular fertilization, which is best done during the growing season. Use a balanced fertilizer with an NPK ratio of 10-10-10 or 15-15-15, following the instructions on the packaging label. Fertilize in small amounts every month rather than applying a large amount in one go.
Pruning
Pruning is a crucial aspect of maintaining the health and aesthetic appeal of Rhus angolensis Engl. forma glabrescens R.Fern. It is recommended to prune during the dry season, removing any dead or diseased branches, and cutting back any overgrown or straggly growth. It is important to use sharp pruning shears to avoid damaging the plant.
Propagation Methods for Rhus angolensis Engl. Forma Glabrescens R.Fern.
There are various methods to propagate Rhus angolensis Engl. Forma Glabrescens R.Fern. These methods include:
1. Seed Propagation
Seed propagation is the easiest and most common method of propagating Rhus angolensis. The seeds can be collected from the ripe fruit and stored in a dry place until they are ready to be planted. The seeds should be scarified or nicked with a knife to improve their germination rate. The seeds can be sown in pots or directly into the ground. They should be planted in well-drained soil and kept moist until they germinate.
2. Cutting Propagation
Cutting propagation is another method of propagating Rhus angolensis. Semi-hardwood cuttings should be taken from the plant during the growing season. The cuttings should be about 10cm in length and should have at least 2 nodes. The bottom part of the cutting should be dipped in rooting hormone and planted in a well-drained soil mixture. The cutting should be kept moist and warm until roots begin to form.
3. Grafting Propagation
Grafting propagation is a method used to propagate Rhus angolensis when it is difficult to root from cuttings. The scion, which is taken from the parent plant, is grafted onto the rootstock of a closely-related but hardier plant. Grafting is a bit more complicated than other propagation methods and should be done by experienced gardeners.
Regardless of the propagation method used, it is important to ensure that the plant is healthy and that the growing conditions are favorable to ensure successful propagation.
Disease and Pest Management for Rhus angolensis Engl. forma glabrescens R.Fern.
Rhus angolensis Engl. forma glabrescens R.Fern. is generally a hardy plant species that can withstand pests and diseases effectively. However, certain factors may affect their health and render the plant vulnerable to various issues. Below is a list of common diseases and pests that may impact the plant and the possible management strategies for each issue.
Diseases
Anthracnose is a fungal disease that causes leaf spots, twigs, and fruits to develop irregular, brown patches. Removing and disposing of infected plant parts and spraying antifungal agents containing copper or sulfur can help manage the disease.
Leaf spot disease causes dark spots to form on the foliage, leading to wilt and leaf drop. Pruning out infected leaves and maintaining proper irrigation and fertilization practices can help reduce the risk of the disease spreading.
Sooty mold grows on honeydew excreted by sucking insects like aphids and whiteflies, resulting in a black, powdery coating on leaves and twigs. Applying insecticidal soap to rid the plant of pests and wiping it off can then prevent the mold from growing further.
Pests
Spider mites are tiny insects that produce visible webbing over the leaves and cause stunted growth. Washing the plant regularly with a strong stream of water or using a miticide spray can help get rid of them.
Thrips are slim, cigar-shaped insects that suck leaves' sap and cause distorted, brown spots. Using sticky traps, spraying the plant with a neem oil-based insecticide, and weeding out infected leaves can help control thrip populations.
Mealybugs are soft-bodied, white insects that disrupt plant growth and produce honeydew that attracts ants. Using neem oil or a mixture of rubbing alcohol and dish soap can help get rid of them.
By taking necessary steps to control the spread of diseases and pests, Rhus angolensis Engl. forma glabrescens R.Fern. can remain a healthy and thriving addition to any garden or landscape.
