Origin
Platanthera orbiculata (Pursh) Lindl. var. macrophylla (Goldie) Luer is a species of orchid that is native to North America. It can be found growing in wetlands and moist meadows in Canada and the United States, particularly in the Midwest region.
Common Names
The plant is commonly known as the large round-leaved orchid or the western prairie fringed orchid. In some regions, it is also called the gray northern bog-orchid.
Uses
Platanthera orbiculata var. macrophylla is primarily used as an ornamental plant. It is prized by horticulturists and collectors for its beautiful flowers, which are often used in floral arrangements. The plant may also have medicinal properties, and some Native American tribes have used it to treat various ailments, including digestive issues and menstrual cramps.
General Appearance
Platanthera orbiculata var. macrophylla is a perennial orchid that can grow up to 3 feet tall. It has large, oval-shaped leaves that can reach up to 8 inches in length. The plant produces tall spikes of fragrant white flowers, which bloom from June to August. The flowers have a distinctive fringed lip and are pollinated by moths. The plant prefers moist soil and partial shade and can be difficult to grow in cultivation.
Growth Conditions for Platanthera orbiculata (Pursh) Lindl. var. macrophylla (Goldie) Luer
Light: Platanthera orbiculata (Pursh) Lindl. var. macrophylla (Goldie) Luer grows best in partial shade to full sun. The plant requires at least 50% sunlight throughout the day. Too much sunlight may cause the leaves to yellow and wilt, while too little sunlight may stunt the growth of the plant.
Temperature: Platanthera orbiculata (Pursh) Lindl. var. macrophylla (Goldie) Luer thrives in cooler temperatures. The plant prefers a temperature range between 10°C to 25°C. Extreme heat or cold may cause damage to the plant. During the winter months, the plant goes dormant and should be kept in a cooler environment.
Soil: Platanthera orbiculata (Pursh) Lindl. var. macrophylla (Goldie) Luer grows best in well-drained, moist soil. The plant prefers soil that is slightly acidic with a pH range between 5.5 and 6.5. The soil should be rich in organic matter, and the plant benefits from regular fertilizing. The roots of the plant are fragile and can be easily damaged, so care should be taken when transplanting.
Cultivation Methods:
Platanthera orbiculata (Pursh) Lindl. var. macrophylla (Goldie) Luer is a terrestrial orchid species that requires partial sunlight or dappled shade. This plant grows well in well-drained soil that is rich in organic matter and moisture-retentive. It is crucial to keep the soil damp during the growing stage, and a good drainage system is necessary to prevent waterlogging. The ideal planting time is during spring, and new plants should be planted 10-20cm apart.
Watering Needs:
Orchids require consistent watering, but overwatering should be avoided, as soggy soil can lead to root rot. During the growing stage, it's best to keep the soil just damp. During winter, the water supply should be reduced, but the plant should not be completely dry. The key is to maintain moisture without allowing water to sit on top of the soil. Rainwater or distilled water is better for watering orchids, as tap water may contain chlorine and other chemicals that can harm the plant.
Fertilization:
Fertilizers are essential for the healthy growth of orchids. During the growing stage, a balanced 20-20-20 NPK fertilizer every two weeks will suffice. In winter, the fertilizer supply should be reduced or stopped altogether. Avoid using fertilizers that are high in nitrogen, as this can result in leafy growth without flowers.
Pruning:
Orchids require minimal pruning, only removing dead or damaged leaves and stem. Flowers should be deadheaded to encourage new growth and blooming. If the plant outgrows its pot, transplantation should be done in the spring.
Propagation of Platanthera orbiculata (Pursh) Lindl. var. macrophylla (Goldie) Luer
Platanthera orbiculata (Pursh) Lindl. var. macrophylla (Goldie) Luer, commonly known as large round-leaved orchid or western northern bog orchid, is a terrestrial orchid native to North America. The plant typically grows in wetland habitats such as bogs, fens, and swamps. It produces attractive flowers that bloom in late summer.
Propagation of Platanthera orbiculata (Pursh) Lindl. var. macrophylla (Goldie) Luer can be challenging as the plant has specific requirements for growth. The following propagation methods can be used to propagate the plant:
Seed Propagation
Seed propagation is the most common method used to propagate Platanthera orbiculata (Pursh) Lindl. var. macrophylla (Goldie) Luer. The plant produces small seeds that are dust-like and require a fungal partner to germinate. The seeds are sown on moist sphagnum moss and kept at a constant temperature of 20 to 25°C. They should be kept moist at all times.
After germination, the seedlings are transferred to small pots with a mixture of sphagnum moss and perlite. Once the seedlings reach a size of 5 cm, they can be planted in their final growing location.
Division Propagation
Division propagation involves dividing the rhizomes of mature plants into smaller sections and planting them in suitable growing conditions. This method is best done in the fall after the plant has completed its growing season and is dormant.
The rhizomes should be lifted from the ground using a garden fork and gently shaken to remove any excess soil. The rhizomes are then separated into smaller sections, each with at least one growing point. The sections are planted in humus-rich, well-draining soil in a shaded area.
It is important to ensure that the soil remains moist, but not waterlogged, until new growth appears. Once the plants have established themselves, they can be transplanted into a permanent growing location.
Disease Management
Platanthera orbiculata (Pursh) Lindl. var. macrophylla (Goldie) Luer is susceptible to various types of fungal diseases, including powdery mildew, rust, and Botrytis blight. To control powdery mildew, ensure adequate air circulation around the plant and avoid overhead watering. Applying fungicide sprays can also prevent the spread of powdery mildew. Rust can be controlled by removing infected leaves and applying a fungicide spray. Botrytis blight can be prevented by avoiding over-irrigation, removing infected plant parts, and applying a fungicide spray.
Pest Management
Platanthera orbiculata (Pursh) Lindl. var. macrophylla (Goldie) Luer is not commonly affected by pests. However, some insect pests that may infest this plant include aphids, spider mites, and thrips. Aphids can be controlled by washing them off the plant with a strong water spray or by applying insecticidal soap. Spider mites and thrips can be controlled by washing them off the plant with water or by applying insecticidal soap or a miticide spray.
