Origin
Cleistanthus polystachyus Hook.f. ex Planch. subsp. polystachyus is a plant species native to Southeast Asia, particularly in the countries of Malaysia, Indonesia, and the Philippines.
Common Names
Common names for Cleistanthus polystachyus Hook.f. ex Planch. subsp. polystachyus include "fish poison tree," "peninsular white siris," and "white siris".
Uses
The plant has been traditionally used for medicinal purposes. Cleistanthus polystachyus Hook.f. ex Planch. subsp. polystachyus contains toxic compounds called cleistanthin A and B which has been utilized by indigenous people for fishing. These compounds are said to cause the fish to become drowsy making it easier to catch them. Currently, the plant's extracts are researched due to its cytotoxic, antifungal and possible anticancer properties.
General Appearance
Cleistanthus polystachyus Hook.f. ex Planch. subsp. polystachyus is a shrub that typically grows up to 10 meters in height. The leaves are alternate, simple, and ovate-oblong in shape. They are glossy green on the upper surface and lighter-colored beneath. The flowers are small, greenish-white, and arranged in inflorescence of cylindrical spikes. The fruits are capsules that are round, brown, and contain numerous seeds.
Light Requirements
Cleistanthus polystachyus is a shade-loving plant that prefers partial to full shade. It can tolerate some direct sunlight, but prolonged exposure to full sunlight can harm its leaves and reduce growth. Therefore, it is best to keep the plant in a spot that receives bright, indirect sunlight or filtered shade. To ensure healthy growth, it is important to avoid exposing the plant to intense heat or strong winds.
Temperature Requirements
The optimum temperature range for Cleistanthus polystachyus growth is between 20 to 30 degrees Celsius. Generally, it is a hardy plant that can tolerate a moderate level of temperature fluctuation. However, extreme low or high temperatures can impact its overall growth and development. During colder months, the plant should be protected from frost and freezing temperature by moving it indoors or covering it with a protective layer.
Soil Requirements
Cleistanthus polystachyus prefers well-drained and fertile soil with a slightly acidic to neutral pH level of between 6.0 to 7.0. The soil should be rich in organic matter and have good water retention capacity. The plant can thrive in various soil types such as sandy, loamy, or clayey soil, but it does not tolerate waterlogged or compacted soil. Therefore, it is essential to ensure that the soil is adequately amended for good drainage before planting. Additionally, a regular supply of nutrients through organic fertilizers or compost will help to maintain the soil quality and support the plant's growth.
Cultivation Methods
Cleistanthus polystachyus Hook.f. ex Planch. subsp. polystachyus grows best in well-draining soils with a pH range of 6-7.5. The plant prefers full sun to partial shade and can be grown both indoors and outdoors.
Watering Needs
The plant requires moderate watering, with soil moisture being allowed to dry out between watering. During the growing season, consistent and regular watering is recommended. However, it is essential to avoid overwatering since this can lead to root rot and pest problems.
Fertilization
Cleistanthus polystachyus Hook.f. ex Planch. subsp. polystachyus growth can be improved by regular fertilizing using a high nitrogen fertilizer, especially during the growing season. Fertilizer application should be done according to the manufacturer’s instructions. However, it is essential to avoid overfertilization as this can lead to leaf burn and poor growth.
Pruning
Pruning should be done during the growing season to encourage a thick and bushy growth habit and limit its height. Cutting the top growth of the plant back can encourage lateral shoots to grow, leading to a fuller shape. Any yellowing or dead leaves should also be removed to maintain a healthy and aesthetically pleasing plant.
Propagation methods
There are different methods of propagating Cleistanthus polystachyus Hook.f. ex Planch. subsp. polystachyus, including seeds, cuttings, and layering. Each method has its advantages and disadvantages, and the choice of propagation method depends on the grower's preferences and available resources.
Seeds propagation
Propagating Cleistanthus polystachyus Hook.f. ex Planch. subsp. polystachyus from seeds is the most common and easiest method. The seeds require stratification, a process of exposing them to cold temperatures to simulate natural winter conditions. This treatment is necessary to break the seed dormancy and promote germination. After stratification, plant the seeds in a well-draining potting mix, cover them with a thin layer of soil, and keep them moist. The seeds should germinate in two to three weeks, and the seedlings can be potted up into larger containers when they outgrow their pots.
Cuttings propagation
Propagating Cleistanthus polystachyus Hook.f. ex Planch. subsp. polystachyus from cuttings is a more advanced method that requires some skill and knowledge. The cuttings should be taken from mature, healthy plants in the spring or summer when the plant is actively growing. Use a sharp knife or pruning shears to cut a stem that is 5-10 cm long, remove the lower leaves, and dip the cut end into rooting hormone powder. Insert the cutting into a potting mix or soil that drains well, water it thoroughly, and cover it with a clear plastic bag to create a mini greenhouse that will retain moisture and help the cutting root. Keep the cuttings in indirect light and maintain the moisture level, and in a few weeks, the cuttings should root and start growing.
Layering propagation
Propagating Cleistanthus polystachyus Hook.f. ex Planch. subsp. polystachyus from layering is a slower method but the easiest to do since it utilizes the parent plant's existing infrastructure. Select a healthy, low-hanging branch and remove a strip of bark with a sharp knife. Apply rooting hormone to the wound area and cover it with moist sphagnum moss. Wrap plastic wrap around the moss and secure it in place with tape or twine. Check the moss periodically to ensure it is moist and that roots are forming. Once roots have formed, cut the layered branch from the parent plant and pot it up.
Disease Management
Cleistanthus polystachyus Hook.f. ex Planch. subsp. polystachyus is vulnerable to fungal and bacterial diseases. Here are some common diseases that affect the plant and ways to manage them:
- Leaf Spot: This disease is caused by fungi and appears as small circular spots on the leaves. To manage this disease, remove the infected leaves and discard them. Use a fungicide spray to prevent the spread of the disease.
- Anthracnose: This disease is caused by fungi and appears as brown, circular lesions on the leaves and stems. To manage this disease, prune the infected areas and discard them. Use a fungicide spray to prevent the spread of the disease.
- Bacterial Blight: This disease is caused by bacteria and appears as brown spots on the leaves and stems. To manage this disease, prune the infected areas and discard them. Use a bactericide spray to prevent the spread of the disease.
Pest Management
Cleistanthus polystachyus Hook.f. ex Planch. subsp. polystachyus is susceptible to insect pests that can cause significant damage to the plant. Here are some common pests that affect the plant and ways to manage them:
- Aphids: These sap-sucking insects are a common pest for Cleistanthus polystachyus Hook.f. ex Planch. subsp. polystachyus. To manage aphids, spray the plant with insecticidal soap or neem oil. You can also introduce natural predators like ladybugs to control the pest population.
- Scale Insects: These insects are small, flat, and oval-shaped, and they can cause significant damage to the plant. To manage scale insects, use an insecticide spray, prune the heavily infested areas, and clean the plant with a soft brush or cloth.
- Spider Mites: These tiny pests are not insects, but arachnids. They can thrive in hot, dry conditions and cause significant damage to the leaves. To manage spider mites, spray the plant with insecticidal soap or neem oil. You can also introduce natural predators like ladybugs to control the pest population.
