Overview of Polystachya melanantha Schltr.
Polystachya melanantha Schltr. is a species of orchid that belongs to the family Orchidaceae. It is commonly known as the black-flowered Polystachya or the African false-vanilla orchid. It is widely distributed across several African countries, including Cameroon, Gabon, Congo, and Angola.
General Appearance of Polystachya melanantha Schltr.
The black-flowered Polystachya is a small-sized epiphytic orchid that grows up to 20cm tall. This species has a single upright stem and is characterized by a clump of thin and elongated leaves that can reach up to 10cm in length. The plant produces numerous tiny black or dark purple flowers that grow on upright spikes, which emerge from the base of the leaves. The flowers of Polystachya melanantha Schltr. are star-shaped with a prominent lip and measure about 1.5cm in diameter.
Uses of Polystachya melanantha Schltr.
In indigenous African medicine, Polystachya melanantha Schltr. is used to treat various ailments such as toothache, diarrhea, and fever. The leaves and flowers of this plant are also used to make tea or a decoction, which is then consumed for their medicinal properties. Furthermore, the black-flowered Polystachya is also a popular choice among orchid enthusiasts and collectors due to its unique appearance.
Light Requirements
Polystachya melanantha Schltr. requires bright, filtered light to grow properly. It can tolerate some direct sunlight in the morning or evening, but intense afternoon sunlight can damage the plant.
Temperature Requirements
The ideal temperature range for Polystachya melanantha Schltr. is between 18°C to 30°C. They prefer warm temperatures but cannot tolerate extreme heat or cold.
Soil Requirements
Polystachya melanantha Schltr. grows best in well-draining soil with high organic content. The soil should be kept moist but not waterlogged. It is recommended to use a potting mix that contains sphagnum moss, perlite, and bark chips.
Cultivation Methods for Polystachya Melanantha Schltr.
The Polystachya Melanantha Schltr., commonly known as the black-flowered Polystachya, is an orchid variety native to Madagascar, Southern Africa. It is a tropical plant that thrives well under warm and humid conditions.
The ideal conditions for cultivating Polystachya melanantha are bright indirect light, a temperature range of 75? - 85 ?, and high humidity. These plants need well-draining soil, which is slightly acidic, and a shallow pot that can support its rhizomes.
You may also grow Polystachya melanantha plant onto a slab of cork, bark, or fern, as this will simulate its natural habitat, especially for the epiphytic species.
Watering Needs for Polystachya Melanantha Schltr.
Polystachya melanantha Schltr. requires consistent watering to thrive well. Provide water at least two to three times every week, but ensure not to overwater the plant as excess water can lead to root rot.
Ensure that the potting mixture is almost dry before watering your Polystachya Melanantha Schltr. You can also use a moisture meter to check the level of water in the soil before watering.
If you grow your plant on a slab, you can mist it every day to keep the leaves and roots hydrated.
Fertilization
Polystachya melanantha Schltr. requires regular fertilization to promote healthy growth. Apply fertilizers to the potting mixture at least once in every two weeks, preferably with a balanced fertilizer, such as 12-12-12 or 20-20-20.
Ensure to dilute the fertilizer to half strength to avoid excess salt build-up in the potting mixture, which can lead to burning of the roots of the plants.
Besides the regular fertilizer, it would be best to apply calcium and magnesium once every month to supplement the nutrient deficiency that may arise due to frequent water usage.
Pruning
Polystachya melanantha Schltr. requires minimal pruning to maintain its health and beauty. Dead or rotting leaves and stems should be pruned off to avoid the spread of diseases to other healthy parts of the plant.
You can also remove the faded flowers to encourage the growth of new flower spikes. Before cutting off the flower spike, ensure that the spike has turned brown and dry. The best place to cut the flower spike is just above the last flower node.
It would be best to sterilize the trimming tools with alcohol before pruning to avoid spreading diseases to other healthy parts of the plant.
Propagation of Polystachya melanantha Schltr.
Polystachya melanantha Schltr. can be propagated through various methods, including:
Division
Division is the most common method of propagation for Polystachya melanantha Schltr. This method involves separating the plant's pseudobulbs and replanting them in a pot. It is best to perform this task during the active growth period, which is in the spring or early summer. All you need to do is remove the plant from its pot, divide the pseudobulbs, and then plant each division in a suitable-sized pot.
Back Bulbs
Back bulbs are a group of old and matured bulbs that have been replaced by newer ones. They are usually located at the back of the plant, away from the new growth. These back bulbs can be removed and replanted to propagate Polystachya melanantha Schltr. To do this, carefully remove the back bulbs from the mother plant, then plant them in a suitable-sized pot, making sure that each back bulb has at least one new growth.
Keiki Cloning
In some cases, you may notice small plantlets or offshoots growing on the mother plant. These offshoots are called keikis. Keikis can be detached from the mother plant and replanted to produce a new plant. Simply remove the keiki from the mother plant, plant it in a suitable-sized pot, and water it regularly. After some time, the keiki will grow into a mature plant.
Seed Propagation
Polystachya melanantha Schltr. can also be propagated through seed. However, this method is relatively challenging and requires specialized equipment. It is best to leave seed propagation to experienced growers or horticulturists.
Disease and Pest Management for Polystachya melanantha Schltr.
Polystachya melanantha Schltr., also known as the Black-stemmed Polystachya, is a beautiful epiphytic orchid that is native to Africa. Like all plants, it is susceptible to various diseases and pests. Here are some common problems that might affect this orchid and how you can manage them:
Diseases
Crown rot: Crown rot is a fungal disease that affects the base of the plant near the soil surface and can be fatal if not treated promptly. Symptoms include wilting, yellowing, and softening of the crown area. To manage this disease, remove affected plant parts, repot the orchid in fresh potting mix, and improve ventilation and drainage.
Bacterial soft rot: Bacterial soft rot is a bacterial disease that causes soft, slimy spots on the leaves, pseudobulbs, and roots. This disease can cause the plant to die if left untreated. To manage this disease, remove affected plant parts, improve ventilation and drainage, and avoid overwatering.
Leaf spot: Leaf spot is a fungal disease that causes brown, black, or yellow spots on the leaves. Severe infections can cause the leaves to fall off, and in severe cases, the plants can die. To manage this disease, remove affected plant parts, improve ventilation, and avoid wetting the leaves when watering.
Pests
Scale insects: Scale insects are small, flat, round insects that attach themselves to the leaves and pseudobulbs of the orchid, sucking the plant's sap. This can cause wilting, stunted growth, and sometimes death. To manage these pests, remove them manually with a soft brush or cotton swab dipped in rubbing alcohol.
Spider mites: Spider mites are tiny pests that suck the plant's sap. They can be identified by the presence of fine webbing on the leaves and pseudobulbs, yellowing leaves, and stunted growth. To manage these pests, isolate the infected plants, increase humidity, and spray the plants with insecticidal soap or neem oil.
Thrips: Thrips are small, slender insects that feed on the flowers and leaves of the orchid plant, causing deformed flowers, yellowing leaves, and silvery patches on the foliage. To manage these pests, remove affected plant parts, isolate the infected plants, and spray the plants with insecticidal soap or neem oil.
By following these tips, you can keep your Polystachya melanantha Schltr. healthy and free from diseases and pests.
