Origin and Common Names
Rhus coriacea Engl. is a species of flowering plant that belongs to the family Anacardiaceae. This plant is commonly known as the African sumac, mountain currant, or rock currant, and it is native to South Africa.
General Appearance
As a shrub or small tree, Rhus coriacea Engl. can reach a height of up to four meters. The plant is typically multi-stemmed with a rounded, spreading canopy. It has a relatively thin and smooth bark with several branches that are angled upwards. The leaves are large, leathery, and dark green. Moreover, the inflorescence of Rhus coriacea Engl. is a small and dense panicle of greenish-white flowers that are highly fragrant.
Uses
The African sumac, Rhus coriacea Engl., is a highly versatile plant with various uses in modern and traditional medicine and horticulture. The leaves of Rhus coriacea Engl. contain natural compounds, such as tannins and flavonoids, which are beneficial as anti-inflammatory and astringent agents. The extract obtained from the plant also provides relief from rashes, skin irritation, and digestive issues. In horticulture, the African sumac can be used as an ornamental garden plant, and also has soil stabilizing properties, making it useful in erosion control and restoration projects.
Additionally, the plant is an excellent source of nectar for bees and other pollinators and is an essential component in the ecology of the regions it grows. It is known for its drought-resistant qualities and is often utilized for reforestation, especially in arid areas where other plants may struggle to survive.
Growth Conditions for Rhus coriacea Engl.
Rhus coriacea Engl. is a shrub endemic to the higher elevations of the Canary Islands. It is commonly known as "Candelilla" due to its candle-like appearance. The plant's typical growth conditions include:
Light
Rhus coriacea Engl. thrives in bright sunlight or partial shade. It is best to place the plant in an area where it can receive direct sunlight for at least four hours a day. Too little light can cause the plant to grow weak and leggy, while too much sun may scorch its leaves and damage the plant.
Temperature
The plant grows best in warm temperatures. It can tolerate a range of temperatures, but it prefers a range of 10 to 30°C. If the temperature falls below 10°C, the plant may become dormant, and if it exceeds 30°C, its growth may slow down or stop.
Soil Requirements
Rhus coriacea Engl. requires well-draining, nutrient-rich soil to grow well. The plant thrives in slightly acidic to neutral soils (pH 6.5 to 7.5). It prefers soils that are rich in organic matter and can retain moisture at the same time. Ensure the soil is not waterlogged, as this may lead to root rot and fungal diseases.
Regular watering is necessary during the growing season, but not too much to cause waterlogging. Fertilize the plant during the growing season (spring and summer) with a balanced fertilizer to support its growth and development.
Cultivation methods
Rhus coriacea Engl., commonly known as African sumac or karree, is a hardy plant that can survive in a variety of climates. It prefers well-drained soil and can grow in either full sun or partial shade. The plant is propagated by seed or cuttings and should be planted in the spring or fall. It requires minimal care once established.
Watering needs
African sumac requires moderate watering, particularly during the first year after planting. The soil should be allowed to dry out slightly before watering again, as the plant is susceptible to root rot in excessively moist soil. In drought conditions, regular watering may be necessary to maintain the plant's health.
Fertilization
Fertilization is not essential for African sumac, as it can thrive in nutrient-poor soil. However, adding a balanced fertilizer in early spring can encourage healthier growth and flowering.
Pruning
Pruning is not necessary for the African sumac, and it can grow into a large shrub or small tree if left alone. However, if pruning is desired, it should be done during the dormant season to avoid damaging the plant. Dead or damaged branches should be removed, and shaping can be achieved by selectively trimming branches.
Propagation of Rhus coriacea Engl.
The Rhus coriacea Engl., commonly known as the African sumac, can be propagated by various methods, including:
Seed Propagation
Rhus coriacea seeds can be collected from mature fruits and sown directly into a well-draining soil mixture. The ideal time for seed collection is in late spring to early summer. Stratification treatments may be essential to enhance seed germination. Seedlings need to be kept in a warm environment and provided with ample sunlight.
Cutting Propagation
Rhus coriacea can be propagated using semi-hardwood cuttings. The cuttings must be around 10-15 cm long and taken during spring or summer. The cuttings should be dipped into a rooting hormone and planted into a well-draining soil mix. The cuttings must be kept at a temperature of 18-23°C and in a location with bright, indirect light. Rooting of the cutting may start after six weeks.
Grafting Propagation
Grafting can be used for Rhus coriacea to maintain the desired characteristics of the parent plant. It can also be used to increase the vigor and strength of the plant. Grafting can be done by the methods of budding or whip grafting. Rhus coriacea is compatible with a range of rootstocks such as Rhus laurina, Rhus ovata, and Rhus integrifolia.
Disease Management for Rhus coriacea Engl.
Plant diseases are common in Rhus coriacea Engl., and they can cause a significant impact on their growth and yield. Here are some of the prevalent diseases that affect Rhus coriacea Engl.:
- Anthracnose: Anthracnose is a fungal disease that causes defoliation, twig dieback, and cankers on the stem. It can spread through infected plant debris or by spores that disperse in the wind. Infected areas should be promptly pruned and destroyed. Fungicides can be used to control the spread of anthracnose.
- Bacterial Leaf Spot: Bacterial leaf spot causes small yellow spots that turn brown or black, eventually leading to defoliation. It can spread through water, wind, or insects. Affected leaves should be pruned and destroyed, and the plant should be sprayed with copper-based fungicides.
- Phytophthora Root Rot: Phytophthora root rot affects the plant's roots and causes wilting, yellowing, and stunted growth. It can be prevented by ensuring proper drainage, avoiding waterlogging, and planting in well-drained soils.
Pest Management for Rhus coriacea Engl.
Pests can cause damage to Rhus coriacea Engl. in the form of leaf-eating, stem-boring, and root-feeding. Here are some of the prevalent pests that affect Rhus coriacea Engl.:
- Caterpillars: Caterpillars can cause defoliation, leaving behind skeletonized leaves. Handpicking caterpillars and using Bacillus thuringiensis-based insecticides can help manage caterpillar populations.
- Spider Mites: Spider mites suck sap from the plant, causing the leaves to wilt and turn yellow. They can be controlled by maintaining high humidity levels and using insecticidal soap and miticides.
- Scale Insects: Scale insects attach themselves to the plant's stems and leaves, causing yellowing, stunted growth, and defoliation. They can be managed by pruning affected branches, using horticultural oils, and systemic insecticides.
Regular monitoring and early identification of disease and pest problems can help minimize damage to Rhus coriacea Engl. Effective management strategies will depend on the specific problem and severity of the issue.
