Overview
Parmeliella praetermissa, also known as the forgotten shield lichen, is a species of lichen in the Parmeliaceae family. It is an epiphytic lichen found throughout North America on the bark of trees, especially on conifers. It is commonly found in humid and cool habitats such as forests and mountains.
Appearance
Parmeliella praetermissa forms a foliose thallus that ranges in size from several centimeters to over 20 centimeters in diameter. It has a brownish-grey color, with a smooth upper surface and a textured underside. The lobes are flat and broad, and the margins are curled upward. The thallus is also covered in small, black, dot-like structures known as apothecia.
Common Names
Parmeliella praetermissa is commonly referred to as the forgotten shield lichen due to its ability to go unnoticed and overlooked in its habitat.
Uses
In traditional medicine, Parmeliella praetermissa has been used as a remedy for respiratory tract infections, skin diseases, and digestive disorders. It contains a variety of compounds with potential pharmaceutical and industrial applications. Additionally, it serves as an ecological indicator for air pollution, as it is sensitive to sulfur dioxide and other pollutants present in the atmosphere.
Overall, Parmeliella praetermissa is an important species in the ecosystem, and its unique characteristics and uses make it a valuable lichen species for both ecological and medicinal purposes.Light Requirements
Generally, Parmeliella praetermissa prefers moderate shade and dappled sunlight. It can tolerate full sun exposure but only in high-altitude areas with lower temperatures and high humidity. Direct, intense sunlight can cause damage to the thallus and may restrict its growth. So when cultivating Parmeliella praetermissa, it is advisable to provide partial shade to the plant.
Temperature Requirements
The optimal temperature range for Parmeliella praetermissa growth is between 15-25°C. It can withstand temperatures of up to 30°C but only for a short period. Extremely hot temperatures (above 35°C) can damage the thallus, leading to stunted growth and lowering photosynthetic activity. On the other hand, temperatures lower than 10°C can cause dormancy or death of the plant. Therefore, consistent temperatures within the optimal range are essential for the cultivation of Parmeliella praetermissa.
Soil and Nutrient Requirements
Being a lichen, Parmeliella praetermissa grows on various substrates, such as pebbles, rocks, bark, and twigs. It is more likely to thrive in habitats that have fewer pollutants and conducive to the growth of its symbiotic partners, the algae, and fungi. Though Parmeliella praetermissa thrives in nutrient-poor environments, some key nutrients are necessary for its survival. These elements include potassium, calcium, and magnesium, which aid in the thallus growth and the photosynthetic activity of the plant. Similarly, nitrogen and phosphorus are crucial components of the lichen and aid in the formation of new thalli. Therefore, it is necessary to provide a substrate that has low acidity and moderate nutrient availability when cultivating Parmeliella praetermissa.
Cultivation Methods
Parmeliella praetermissa is a species of lichen that thrives in warm and humid conditions. The best way to cultivate this species is by propagating its thallus fragments on a substrate such as a tree branch or a rock. The substrate should be resistant to decay and sterilized before planting.
To propagate, the thallus fragments need to be cut into small pieces and placed on the substrate. Then, it should be tied with a string or a wire and hung in an open place with indirect sunlight. After about six months, the thallus fragments will have colonized the substrate and can be moved to its growing location.
Watering Needs
Parmeliella praetermissa is a drought-tolerant plant that thrives in humid conditions. However, it needs occasional moisture to survive. It is important to keep the substrate moist but not wet. The lichen should be watered once every two weeks during the growing season and once every month during the dormant season.
Fertilization
Parmeliella praetermissa does not require fertilization as it obtains its nutrients from the surrounding environment. However, you can apply a liquid fertilizer once every six months during the growing season to provide it with the necessary nutrients.
Pruning
Parmeliella praetermissa does not require pruning as it is a slow-growing plant that does not easily overgrow its container or substrate. However, any dead lichen should be removed to prevent the spread of disease or pests.
Propagation of Parmeliella praetermissa
Propagation of Parmeliella praetermissa can be done in various ways, and it mostly depends on the specific growth habits of the plant. One of the ways to propagate Parmeliella praetermissa is by dividing the thallus. This method involves separating a portion of the plant's thallus and transplanting it somewhere else. Parmeliella praetermissa's thallus can be easily divided with a sharp knife or blade.
Another option for propagating Parmeliella praetermissa is through vegetative propagation. This method involves using fragments of Parmeliella praetermissa's thallus, which are then grown into new plants. The fragments can be collected from various parts of the plant and then planted in suitable growing conditions.
Propagating Parmeliella praetermissa can also be done through spores. Spores are small reproductive structures that can be found on the surface of the plant. To propagate Parmeliella praetermissa through spores, a spore print is collected and dispersed into a suitable growing medium. The spores will then grow into new plants.
It's important to note that Parmeliella praetermissa thrives in specific growing conditions. It prefers a humid environment, moderate to low light, and good air circulation. When propagating Parmeliella praetermissa, it's crucial to ensure that the new growth environment matches these conditions to promote healthy development.
Disease Management for Parmeliella praetermissa
Like other plants, Parmeliella praetermissa is susceptible to diseases that may cause damage to the crops and reduce yield. The common diseases that affect the plant include:
- Anthracnose: This disease is caused by a fungus and is characterized by the appearance of brown or black spots on the leaves, stems, and fruits. To manage this disease, use of fungicides and planting resistant varieties is recommended.
- Leaf spot: This disease also caused by a fungus, causes the leaves of the plant to develop unsightly spots. To manage this disease, removal of infected plant parts and use of fungicides are recommended.
- Bacterial Blight: This disease is caused by bacteria and is characterized by the appearance of water-soaked lesions on leaves and stems. To manage this disease, removal of infected plant parts and use of copper-based fungicides are recommended.
Pest Management for Parmeliella praetermissa
Aside from diseases, pests can also cause significant harm to Parmeliella praetermissa. The common pests that might affect the plant include:
- Aphids: These small insects can cause significant damage to plants by sucking sap from the leaves. To manage this pest, use of insecticidal soap or neem oil is recommended.
- Spider mites: These tiny pests can cause damage to the leaves of the plant by sucking the sap, which leads to yellowing of the leaves. To manage this pest, use of insecticidal soap or neem oil is recommended.
- Thrips: These pests cause damage by sucking sap from the leaves or flowers, and by leaving behind scars. To manage this pest, use of insecticidal soap or neem oil is recommended.
Regular inspection of the plant for signs of disease or pest infestation is essential for early detection and management of the problem. Additionally, planting resistant varieties, crop rotation, and good cultural practices such as proper watering and adequate fertilization can help to prevent disease and pest problems.
