Overview
Polystachya albescens Ridl. subsp. albescens is an epiphytic orchid species native to tropical Africa and found in countries such as Liberia, Ghana, Uganda, and Tanzania. It is a highly sought-after plant due to its ornamental value and the medicinal properties of its extracts.
Common Names
The plant is commonly known as the White Polystachya, African Vegetable Orchid, and the Lizard Orchid.
Uses
The Polystachya albescens Ridl. subsp. albescens has been used for various medicinal purposes in Africa. The roots of the plant contain certain alkaloids that have been used to treat diseases such as diabetes, malaria, and fever. Besides, the leaves of the plant are used traditionally as a vegetable in some parts of Africa. Women in Tanzania are known to use this plant's paste to relieve headaches, toothaches and increase breast milk production. In the Western world, the plant is grown for ornamental purposes due to its beauty.
General Appearance
The Polystachya albescens Ridl. subsp. albescens is a medium-sized orchid with an upright habit. The plant's stem is slender, branching, and can reach up to 40 cm in length. The leaves are fleshy, leathery, and dark green. They grow in pairs, are oblong-shaped, and approximately 12cm long by 4cm wide. The flowers are multiple, small, and fragrant, with a creamy-yellow hue. Each blossom has a lip that is wide and tube-like, with a distinctive brown pattern on the inside. The plant's roots are thin, long, and white, and wrap tightly around the host tree or growing medium for support.
Light Requirements
Polystachya albescens Ridl. subsp. albescens typically grows in areas with bright, indirect light or partial shade. It should be protected from direct sunlight, which can scorch its leaves, but still requires adequate light to thrive.
Temperature Requirements
Polystachya albescens Ridl. subsp. albescens prefers a warm and humid environment. It is suitable for growing in areas with temperatures between 15 °C to 25 °C during the day and 10 °C to 15 °C at night. Exposure to lower temperatures may cause stunting and yellowing of its leaves.
Soil Requirements
Polystachya albescens Ridl. subsp. albescens grows best in a well-draining medium that is rich in organic matter. It is an epiphytic plant that can grow on the bark of trees or rocks. Using a potting mixture that mimics these conditions is ideal, such as a blend of bark, sphagnum moss, and perlite. The pH level should be slightly acidic, between 5.5 and 6.5, to prevent mineral toxicity.
Cultivation Methods
Polystachya albescens Ridl. subsp. albescens is an epiphytic orchid that thrives when grown in a greenhouse, conservatory, or outdoors in tropical or subtropical regions. It prefers bright but indirect light and should be sheltered from direct sunlight. The plant can be propagated from division and grows well in humid conditions.
Watering Needs
Polystachya albescens Ridl. subsp. albescens needs regular watering, especially during the growing season. The plant should be watered only when the potting mix feels dry to the touch. Rainwater or distilled water is preferable for watering. Avoid using hard water that may contain harmful minerals. It is better to underwater than overwater as excessive moisture may cause root rot.
Fertilization
Polystachya albescens Ridl. subsp. albescens needs regular feeding during the growing season, which is usually from spring to autumn. Use a balanced, water-soluble orchid fertilizer diluted to half the recommended strength. Apply the fertilizer every two weeks, ensuring that the plant is well-watered before applying the fertilizer. Do not fertilize during the dormant season.
Pruning
Polystachya albescens Ridl. subsp. albescens does not require pruning as such, but the plant may need tidying up from time to time. Remove any yellowing or dead foliage with sharp scissors. Cut the spent flower spikes a few inches above the base. If the plant outgrows its container, repot it at the beginning of the growing season, using fresh orchid potting mix.
Propagation of Polystachya albescens Ridl. subsp. albescens
Polystachya albescens Ridl. subsp. albescens is a fascinating orchid species that is native to the rainforests of Africa. It is a semi-terrestrial plant that grows in organic matter on the forest floor. Propagation of this plant can be done through various methods, which include:
Division
One of the simplest ways to propagate Polystachya albescens Ridl. subsp. albescens is through division. It involves separating the plant into two or more sections with at least one new growth and several established roots. The plant should be carefully lifted from the pot, the roots should be gently washed, and the plant should be divided into sections. Each section should then be planted in a new pot with fresh potting mix.
Back bulbs
Back bulbs are the older bulbs on the plant that have already bloomed and are no longer active. These bulbs can be used for propagation if they still have signs of growth. Once removed from the plant, they should be planted in a separate pot with fresh potting mix.
Keiki plantlets
Keiki plantlets are offshoots that grow from the nodes of the mother plant's stem. Polystachya albescens Ridl. subsp. albescens produces keiki plantlets relatively easily, making it an ideal propagation method. The keiki should be carefully removed from the mother plant and planted in its own pot with fresh potting mix.
Seed propagation
Seed propagation is the most challenging method of propagating Polystachya albescens Ridl. subsp. albescens, but it is also the most rewarding. Fresh seed pods should be collected from the plant and allowed to mature. The seeds should be sown on sterile media in a greenhouse. The seeds will usually germinate within a few months, and the seedlings can be transplanted once they are large enough to handle.
Propagation of Polystachya albescens Ridl. subsp. albescens can be a rewarding process that should be undertaken with care, patience, and attention to detail.
Disease Management for Polystachya albescens Ridl. subsp. albescens
Polystachya albescens Ridl. subsp. albescens is a relatively disease-resistant plant. However, it can still be infected by some diseases. Some common diseases that can affect this plant include:
- Bacterial blight
- Root rot
- Crown rot
To manage bacterial blight, remove the infected parts of the plant, sterilize pruning tools in between cuts, and avoid overhead irrigation. To manage root and crown rot, ensure that the plant is not overwatered, improve soil drainage, and avoid waterlogging. In some cases, systemic fungicides may also be used to control these diseases.
Pest Management for Polystachya albescens Ridl. subsp. albescens
Polystachya albescens Ridl. subsp. albescens is also relatively pest-resistant. However, it is not completely immune to pests. Some common pests that might affect this plant include:
- Spider mites
- Scale insects
To manage spider mites, keep the humidity levels high, especially during hot and dry periods, and use insecticidal soap, neem oil, or horticultural oil. To manage scale insects, use rubbing alcohol to wipe the insects off the leaves, or use a systemic insecticide, such as imidacloprid, acephate, or malathion, which can be applied at the base of the plant.
