Overview of Polystachya excelsa Kraenzl.
Polystachya excelsa Kraenzl., also known as the "Tall Orchid," is a species of epiphytic orchid found in Africa and the Arabian Peninsula. This plant is commonly found in Tanzania, Kenya, and Somalia, and it usually grows in dry evergreen forests, bushland, and savannahs near rivers.
Appearance of Polystachya excelsa Kraenzl.
Polystachya excelsa Kraenzl. is a tall orchid that can grow up to 2 meters in height. The stem is slender, and it branches near the top, forming several arching branches. The leaves are dark green and leathery, with a lanceolate shape, and they grow up to 15 cm long and 5 cm broad. Each stem can produce up to 20 spikes, each of which can bear up to 20 yellow-green flowers with a red-orange spot at the base of the lip. The flowers give off a sweet scent and bloom from June to August.
Uses of Polystachya excelsa Kraenzl.
Polystachya excelsa Kraenzl. is a popular ornamental plant that is cultivated for its beautiful flowers and attractive appearance. The plant does not have any significant medicinal or culinary uses, but some African cultures believe that the plant's fragrance can ward off evil spirits. Some native tribes also use the plant to make traditional medicines for treating various ailments, including fever, headache, and stomach ache.
Common Names of Polystachya excelsa Kraenzl.
Polystachya excelsa Kraenzl. is commonly known as the "Tall Orchid," "Leopard Orchid," or "Spotted Orchid." In Tanzania, it is referred to as "Mzungu Mkubwa" in Swahili, which translates to "Big White Man." This name is derived from the fact that the plant's flowers are said to resemble the spotted skin of a leopard, and the yellow-green petals are said to represent the color of a European's skin.
Growth Conditions for Polystachya excelsa Kraenzl.
As a tropical epiphyte, Polystachya excelsa Kraenzl. grows well in warm and humid conditions. Below are the typical growth conditions required for this plant:
Light
Polystachya excelsa Kraenzl. requires bright, indirect light for optimal growth. It should not be exposed to direct sunlight as it can cause the leaves to burn. The best location for this plant is in an area with filtered light, such as under a shaded tree or on a windowsill shaded by a sheer curtain.
Temperature
Polystachya excelsa Kraenzl. prefers warm temperatures between 70-85°F (21-29°C). It can tolerate slightly cooler temperatures but should not be exposed to temperatures below 55°F (12°C). Cold temperatures can stunt the growth of the plant.
Humidity
As a tropical epiphyte, Polystachya excelsa Kraenzl. requires high humidity levels to thrive. It should be misted regularly with water to increase humidity levels around the plant. Alternatively, it can be grown in a terrarium or greenhouse where humidity levels are naturally high.
Soil
Polystachya excelsa Kraenzl. is an epiphytic plant that typically grows on other plants or trees. It does not require soil to grow but can be grown in a well-draining potting mix made of orchid bark, sphagnum moss, and perlite. The mix should be airy to allow for good airflow, prevent waterlogging and prevent the plant from becoming root-bound.
Cultivation
Polystachya excelsa Kraenzl., commonly known as the Dancing-lady orchid, is an epiphytic plant native to tropical Africa. As an epiphyte, it grows on the branches of trees in the wild where it gets filtered sunlight and fresh air. You can cultivate it at home by mimicking its natural environment with a few adjustments.
To start, use a well-draining potting mix that is rich in organic matter and that replicates the loose and crumbly texture of the native growing substrate. When planting, avoid burying the roots deep into the soil as the plant is accustomed to being attached to the bark of trees. Instead, tie the roots onto a piece of bark or mount the plant on driftwood to create a natural-looking habitat.
Watering Needs
The Polystachya excelsa orchid enjoys moist but not soaking wet growing media. Watering should be done when the top layer of the substrate becomes almost dry. The frequency of watering depends on several factors such as humidity, temperature, and the size of the container. During the growing season, which is usually from spring to fall, watering should be more frequent than in winter when the plant enters a dormant stage.
To avoid root rot, it’s essential to provide good drainage and adequate airflow. Water should be able to pass through the growing medium and out of the bottom of the pot. Also, try to avoid getting water on the leaves, especially in cooler conditions where they can quickly cause bacterial or fungal infections.
Fertilization
In their natural habitat, Polystachya orchids receive a constant supply of nutrients from decomposing matter and rainwater. When cultivated indoors, it’s essential to supplement this natural source of nutrition by fertilizing regularly. Fertilizer with an N-P-K ratio of 20-20-20 or 30-10-10 can be used. A small amount of fertilizer should be added to the water every two to three weeks during the growing season only.
Over-fertilizing the plant can lead to root burn and stunted growth. Always follow the instructions on the label carefully, and err on the side of caution.
Pruning
Pruning Polystachya orchids isn’t necessary, but it can help avoid crowding and ensure that the plant grows evenly. If the plant has outgrown its container, it’s time to repot it in a more substantial pot or divide it into smaller plants. Also, remember to remove any dead or yellowing leaves that can cause disease.
Propagation of Polystachya excelsa Kraenzl.
Polystachya excelsa Kraenzl. is an epiphytic orchid that grows natively in tropical African countries such as Cameroon, Gabon, and Nigeria. While it can be propagated through seed, it is more commonly propagated through vegetative means such as division and keiki production.
Propagation through Division
Division is a common method for propagating Polystachya excelsa Kraenzl. It is best to divide the plant during its dormant period, which is usually in late winter or early spring before new growth begins. The division process involves carefully separating the plant's pseudobulbs and ensuring that each portion has enough roots to survive independently.
A clean, sharp knife should be used to make the cuts, and each divided portion should be potted in a suitable medium such as sphagnum moss or bark. The newly divided plants should be given the same care and attention as the parent plant, including proper humidity and light levels.
Propagation through Keiki Production
Keiki production is another method of vegetative propagation that is commonly used for Polystachya excelsa Kraenzl. Keikis are miniature versions of the parent plant that grow from a node along the stem or at the base of the plant. They can be removed from the parent plant once they have developed roots and leaves of their own, and potted in their individual containers.
Keikis can be encouraged to grow by ensuring that the parent plant is receiving the right amount of nutrients and moisture. Using a rooting hormone can also increase the success rate of keiki production.
Overall, Polystachya excelsa Kraenzl. is relatively easy to propagate through division and keiki production, making it an ideal choice for orchid enthusiasts looking to expand their collection.
Disease Management
Polystachya excelsa Kraenzl. is susceptible to various fungal diseases such as Black Spot, Botrytis Blight, and Anthracnose. To manage these diseases, prevention is crucial. Keep the plant in a well-ventilated area with good air circulation, avoid overhead watering, and do not crowd plants. Remove any diseased plant parts and dispose of them immediately. Fungicides can be used, but it's best to use them sparingly.
Pest management
The plant may also be affected by various pests such as scale insects, spider mites, and aphids. For minor infestations, you can wipe pests off with a damp cloth or spray them with a strong blast of water. For more severe cases, insecticidal soap or horticultural oil can be applied, taking care to follow the instructions on the label.
Preventive measures include inspecting plants often and keeping them healthy and clean. Do not overwater or over-fertilize the plant as it can attract pests. Remove any dead plant matter, as it can harbor pests and diseases.
