Overview of Polystachya cultriformis var. occidentalis Kraenzl.
Polystachya cultriformis var. occidentalis Kraenzl. is a small-sized epiphytic orchid with succulent, terete leaves that belong to the family Orchidaceae. The plant is also known as Sword Leaf Polystachya and is native to tropical and subtropical Africa.
Appearance of Polystachya cultriformis var. occidentalis Kraenzl.
The plant has a compact growth habit and can reach up to 8 inches in height. The flowers are small, 1-2 cm in diameter, and appear in clusters on a stalk up to 15 cm long. They are fragrant and have greenish-yellow sepals and petals that are covered with brown, wavy lines. The lip is white or pale yellow with small purple spots.
The leaves of Polystachya cultriformis var. occidentalis Kraenzl. are succulent, grass-like, and have a grayish-green color. They range from 5-15 cm in length and have a terete or cylindrical shape. These leaves are the most distinctive feature of the plant and give rise to its common name, Sword Leaf Polystachya.
Uses of Polystachya cultriformis var. occidentalis Kraenzl.
Polystachya cultriformis var. occidentalis Kraenzl. is a popular plant in the horticultural trade and is often cultivated for use as an ornament. The plant is easy to grow and is a good choice for beginners who are interested in cultivating orchids. As an epiphyte, it grows well in a range of mediums, including orchid bark, sphagnum moss, and tree fern fiber.
In African traditional medicine, Polystachya cultriformis var. occidentalis Kraenzl. is used to treat various ailments such as fever, diarrhea, and wounds. The plant is also known to possess antibacterial and antifungal properties and has demonstrated efficacy against various strains of bacteria and fungi.
Light Requirements
Polystachya cultriformis var. occidentalis Kraenzl. requires bright, filtered light for optimal growth. It can tolerate some direct sunlight, but too much can scorch its leaves. The plant does best when grown under shade cloth or near a window facing east or west, where it can receive morning or afternoon sunlight.
Temperature Requirements
This orchid species needs warm temperatures year-round to thrive. The ideal temperature range for Polystachya cultriformis var. occidentalis Kraenzl. is between 18°C-32°C. It can tolerate temperatures as low as 13°C during the winter, but temperatures below that can cause the plant to suffer damage.
Soil Requirements
Polystachya cultriformis var. occidentalis Kraenzl. grows best in a well-draining, bark-based potting mix. It needs soil that retains some moisture but does not stay wet for extended periods. A recommended mix is three parts orchid bark to one part perlite or other moisture-retaining medium. The plant should be potted in a container that provides good drainage.
Cultivation Methods
Polystachya cultriformis (Thouars) Spreng. var. occidentalis Kraenzl., commonly known as the Sword-shaped Polystachya, is an epiphytic orchid that grows in the humid tropical forests of Africa. To cultivate this orchid, you will need to simulate the natural conditions of its native habitat. This involves providing adequate light, moisture, and air circulation.
The plant can be grown in pots using a suitable orchid mix, or mounted on a piece of bark or a tree trunk. When growing in a pot, it is advisable to choose a well-draining potting mix that comprises small pieces of bark, sphagnum moss, and perlite. Mounted plants can also be attached to a piece of cork bark using fishing line or wire.
Watering Needs
Polystachya cultriformis requires a consistent level of moisture to thrive. It is important to never let the orchid completely dry out, but overwatering should be avoided to prevent root rot. Recently planted orchids will need more frequent watering than established plants.
When growing in a pot, water the plant once a week and allow any excess water to drain out. Mounted orchids will benefit from frequent misting, particularly during hot and dry weather. Monitor the moisture content of the orchid mix or bark by gently inserting a wooden stick or finger into the substrate to check if it's still moist.
Fertilization
Fertilizing Polystachya cultriformis var. occidentalis is essential to encourage healthy growth and promote flowering. The best way to fertilize this orchid is by using a balanced orchid fertilizer. Apply the fertilizer to the plant every fourth watering throughout the growing season (spring to early fall), and reduce the frequency during the winter season.
Avoid applying too much fertilizer, which can damage the plant's roots. Dilute the fertilizer according to the manufacturer's instructions before application. It is also recommended to flush out excess salts that can accumulate in the substrate by periodically watering the plant with clear water.
Pruning
Pruning is an essential part of the care of Polystachya cultriformis. Its leaves and stems can become overgrown or damaged over time, affecting the overall appearance of the plant. When pruning, always use clean and sharp pruning scissors or shears.
Cut back any damaged or dead foliage to the point where the leaf joins the stem. If the stem has become too long, it can also be pruned back to its base. This will encourage new growth to emerge from the dormant nodes along the stem. It is important to prune only during the growing season and avoid pruning during the flowering period, as it may affect the plant's ability to set new buds.
Propagation of Polystachya cultriformis var. occidentalis:
Polystachya cultriformis var. occidentalis can be propagated by various methods, including:
Division:
The plant can be divided during repotting. This method involves separating the clumps of pseudobulbs into smaller segments and then potting them into individual containers. Each segment should have at least 2-3 pseudobulbs and intact roots. This method is best done in the spring when new growth begins to appear.
Seed propagation:
Polystachya cultriformis var. occidentalis can also be propagated from seed collected from the mature capsules. The seeds must be sown as soon as possible because they have a short shelf life. They should be sown onto a suitable growing medium, covered with transparent wrap to maintain humidity levels, and placed in a warm and bright location. Germination should occur within 3-4 weeks, after which the plants can be transplanted into individual containers.
Meristem culture:
This is a specialized technique that involves the propagation of plant tissue in a sterile laboratory environment. It is an advanced method that is mostly done by professional growers. The technique involves excising small tissue samples from the plant and then growing these samples in a nutrient-rich agar medium. This method ensures that the new plants produced will be free from diseases and pests found in the original plant.
Disease Management
Polystachya cultriformis var. occidentalis is a hardy plant, but there are a few diseases that it may encounter. The most common diseases affecting this species are fungal and bacterial diseases. Leaf spot, caused by the fungus Cercospora polystachyae, is a common issue. Sanitation is key in controlling this disease, so make sure to remove infected leaves as soon as possible and avoid overhead watering. Powdery mildew (Erysiphaceae) can also affect this plant; it usually appears as white powdery patches on leaves. Increasing air circulation and reducing humidity can assist in controlling powdery mildew.
Another common disease is rust (Puccinia polystachyae), which appears as orange or reddish spots on leaves. Infected leaves should be removed immediately and destroyed. Fungicides can be used to manage severe cases of rust, but proper plant spacing and good air circulation can prevent the spread of this disease. Finally, bacterial rot is another concern, which is characterized by a softening and browning of the stem tissue. Bacteria can easily spread through pruning equipment, so ensure that equipment is disinfected before use.
Pest Management
Polystachya cultriformis var. occidentalis is a relatively pest-resistant plant. However, thrips and spider mites can sometimes pose a threat to this species. Thrips are tiny insects that cause leaf distortion and discoloration, while spider mites cause leaves to become mottled and discolored. Natural predators can be used to control these pests, such as ladybugs or predatory mites. Insecticidal soap or neem oil spray can be used as a chemical control measure if necessary.
Another common pest that may threaten P. cultriformis var. occidentalis is scale. These insects are difficult to spot as they are often small and attached to the plant's underside. Infested leaves may turn yellow or prematurely drop off. Scale insects can be controlled through the use of insecticides or by physically scraping them off with a small tool or toothbrush. Regularly inspecting plants for signs of scale can help prevent outbreaks.
Overall, proper maintenance and cultivation practices, including regular sanitation, proper spacing, and appropriate watering, can assist in preventing and managing the disease and pest problems that may affect P. cultriformis var. occidentalis.
