Overview of Parmelia physodes (L.) Ach.
Parmelia physodes (L.) Ach. is a species of lichen in the family Parmeliaceae. It is commonly known as the oakmoss lichen or the lungwort lichen. The plant is native to Europe, but it can also be found in other parts of the world. It grows on the branches of trees, rocks, and soil in open forests, parks, and gardens.
Appearance of Parmelia physodes (L.) Ach.
The plant has a thallus or body that is foliose, meaning it is leaf-like in appearance. The thallus is a light-grey or greenish-grey color and can grow up to 10cm wide. It has a wrinkled or crinkled texture with numerous lobes that are flat and broad. The underside of the thallus is black, and it has small root-like structures called rhizines that help it attach to surfaces.
Uses of Parmelia physodes (L.) Ach.
Despite its name, oakmoss lichen is not actually a moss and is not related to true mosses. Instead, it is a lichen that has been traditionally used in perfumes and fragrances. Its earthy and woody scent has been valued in the perfume industry since the 16th century. The lichen also has medicinal properties and has been used as a remedy for respiratory problems such as cough, asthma, and bronchitis.
Additionally, oakmoss lichen has been used for dyeing wool and silk, giving them a yellow or brownish color. The lichen can also indicate air pollution levels as it absorbs pollutants such as sulfur dioxide from the air. Therefore, it may be used as an indicator species in monitoring air quality in urban areas.
Light requirements
Parmelia physodes is a lichen that requires moderate to low levels of light. It can tolerate some direct sunlight, especially in cooler climates, but too much can cause damage to its delicate structure. The lichen typically grows in shaded or partially shaded areas, such as on tree trunks, rocks, or other surfaces that are protected from direct sunlight.
Temperature requirements
Parmelia physodes is a hardy lichen that can survive in a wide range of temperatures. It can grow in both cool and warm environments, ranging from arctic to tropical regions. However, the lichen grows best in cool, damp conditions with temperatures ranging from 10 to 20 degrees Celsius. In dry or hot conditions, it can become dormant to conserve moisture until more favorable conditions arise.
Soil requirements
As a lichen, Parmelia physodes does not require soil for growth but rather a substrate for attachment, such as rocks, tree bark, or other surfaces. The lichen is capable of absorbing nutrients and moisture directly from the air and can grow in a wide range of substrates. However, the lichen prefers to grow on substrates with high levels of calcium, which can benefit its growth and reproduction.
Cultivation Methods
Parmelia physodes can be grown either indoors or outdoors, and it's important to select a location that is suitable for the plant's requirements. The plant grows well in areas with high humidity, and it thrives in bright, indirect sunlight.
When planting outdoors, it is essential to ensure that the location has well-draining soil that is slightly acidic. The ideal pH range for Parmelia physodes is between 5.5-6.5. The plant can also be grown on rocks or walls if there is enough shade in the location.
For indoor cultivation, the plant can be propagated by attaching to a piece of bark using fishing line or glued to a rock. The same conditions for outdoor cultivation apply to indoor cultivation.
Watering Needs
Watering Parmelia physodes is an essential aspect of its care. It is crucial to maintain consistent moisture for the plant, but it is equally important not to overwater the plant. The plant prefers to be misted with water rather than being watered directly.
For outdoor plants, it is best to water the plant in the early mornings to avoid fungal infections.
Indoor plants can be misted at least twice a week, and they should be placed in areas with high humidity.
Fertilization
For Parmelia physodes, little to no fertilization is required. The plant is well adapted to growing on rocks and tree branches, where there are limited nutrients. However, a foliar spray of seaweed or manure tea can be applied once a month to encourage the growth of the lichen.
Pruning
Pruning is not necessary for Parmelia physodes, as it grows slowly and maintains a compact form. However, it is essential to remove any debris or dead parts of the plant to prevent diseases or insect infestations. Dead material can be easily removed by gently brushing or scraping the surface of the plant with a soft brush.
Propagation of Parmelia physodes (L.) Ach.
Parmelia physodes (L.) Ach., commonly known as the Common Greenshield Lichen, is a lichen that can be found growing on tree trunks, rocks, and soil in a range of environments. It is possible to propagate Parmelia physodes through various methods.
Fragmentation
Propagation by fragmentation involves breaking off a part of the parent plant and allowing it to grow into a new plant. In the case of Parmelia physodes, fragmentation is a common method of propagation. The lichen can be carefully cut or broken into smaller pieces and attached to a suitable substrate, such as a rock or tree bark. The fragmented pieces will start to grow and develop into new individuals over time.
Soredia Propagation
Soredia are small reproductive structures that contain a cluster of fungal hyphae and algal cells. These structures can be found on the surface of Parmelia physodes and can be used for propagation. The soredia can be collected from the parent plant and sprinkled onto a suitable substrate. The soredia will then develop into new individuals over time.
Vegetative Propagation
Vegetative propagation in Parmelia physodes involves the formation of new individuals from specific structures called isidia. These structures are small outgrowths that contain both fungal hyphae and algal cells. They are typically found on the margins of the thallus of the lichen. Isidia can be easily removed from the parent plant and attached to a suitable substrate. Over time, the isidia will form new thalli and develop into new individuals.
In conclusion, Parmelia physodes can be propagated through various methods, including fragmentation, soredia propagation, and vegetative propagation. These methods will effectively allow for the creation of new individuals from a single parent plant.
Disease Management
Plant diseases are caused by fungi, bacteria, viruses, and other pathogens. Parmelia physodes is susceptible to several diseases, including:
- Lichen necrosis: This disease leads to the death of the lichen. It is caused by the fungus Lichenostigma elongata. Control measures include pruning the affected parts of the lichen and keeping the area clean and well-ventilated.
- Lichen spot: This is another fungal disease that causes the formation of brown to black spots on the lichen. It is caused by the fungus Opegrapha physodina. Remove infected lichens and avoid overhead watering.
- Lichen scab: This disease causes the formation of crusty patches on the lichen. It is caused by the fungus Verrucaria muralis. Control measures include pruning infected lichens and maintaining proper sanitation practices.
Pest Management
Like all plants, Parmelia physodes is also susceptible to pest infestations. Some of the common pests that may affect this plant include:
- Lichen mites: These tiny, worm-like creatures feed on the thallus of the lichen, causing yellowing or browning of the lichen. Control measures include pruning infected lichens and maintaining proper sanitation practices.
- Lichen scale insects: These insects attach themselves to the lichen and suck the sap out of it, causing stunted growth and yellowing of the lichen. Control measures include pruning infected lichens and using horticultural oils.
- Lichen moths: The larvae of these moths feed on the thallus of the lichen, causing brown spots and defoliation. Control measures include pruning infected lichens and using organic insecticides.
