Overview
Parmotrema internexum (Nyl.) Hale is a species of foliose lichen that belongs to the family Parmeliaceae and is commonly known as rock shield lichen. It is a native species, found in the southeastern United States, Florida, and the Caribbean islands. The lichen colonizes the bark of trees, rocks, and other hard surfaces to form grayish green, leafy clusters.
Appearance
The thallus of Parmotrema internexum is flat and smooth or slightly wrinkled, forming large rosette-like structures. It is grayish green on the upper surface and white beneath, measuring 50–100mm in diameter. The thallus has lobes that extend radially, giving it a circular or rosette-like shape. The lobes are usually 2-5cm long and 3-7mm wide, with rounded tips.
Uses
Parmotrema internexum has been used for centuries in traditional medicine to treat various ailments. It has been reported to have anti-inflammatory, antioxidant, antitumor, antimicrobial, and antiviral properties. It is also used in dyeing wool, silk, and cotton, where it produces shades of green, blue, and gray. The lichen is also used as a bioindicator of air pollution, as it is sensitive to sulfur dioxide and nitrogen oxides present in the environment.
Common Names
Parmotrema internexum is commonly known as rock shield lichen or cobbler's peg lichen. Other names include shield lichen and foliose lichen.
Light Requirements
Parmotrema internexum is a photosynthetic organism, so it requires adequate light for its growth and development. In its natural habitat, it is commonly found growing on the bark of trees, where it receives limited sunlight because of the tree canopy. As a result, it prefers partial shade or filtered light for optimal growth. Excessive exposure to direct sunlight can cause damage to the plant, resulting in stunted growth and wilting of the tips.
Temperature Requirements
Parmotrema internexum thrives in a moderately cool and moist environment. The plant has a high tolerance for a wide range of temperatures but prefers a cool and humid climate for optimal growth. The ideal temperature range for this plant is between 15°C and 25°C. It can also tolerate colder temperatures down to 5°C and hotter temperatures of up to 35°C, but prolonged exposure to extreme temperatures can result in damage to the plant.
Soil Requirements
Being an epiphytic plant, Parmotrema internexum does not require or grow in soil. Instead, it grows on the bark of trees, rocks, and other surfaces. In its natural habitat, it forms a symbiotic relationship with the host tree, which provides nutrients and support. However, if it is cultivated in a greenhouse or at home, it can be grown on a substrate such as bark or a mixture of peat moss and perlite. The substrate should be moist but not waterlogged, as this can lead to root rot and other diseases.
Cultivation Methods for Parmotrema internexum (Nyl.) Hale
Parmotrema internexum (Nyl.) Hale is a type of foliose lichen that is commonly found growing on tree trunks or on rocks in the forest. As a lichen, it does not have roots, but it can still be cultivated and grown in controlled environments to ensure its optimal growth. To cultivate Parmotrema internexum, you will need to follow a few basic steps.
- First, you will need to obtain a healthy sample of Parmotrema internexum from the wild or a reputable supplier.
- Second, prepare a growth substrate that is similar to the natural environment of Parmotrema internexum. This may include a mixture of soil, sand, and peat moss.
- Third, attach the lichen sample to the substrate using a non-toxic adhesive such as glue or dental floss.
- Fourth, place the lichen in a container or pot with good drainage to avoid waterlogging.
- Fifth, keep the container in a location with moderate to bright, indirect light and good air circulation but avoid direct sunlight.
- Sixth, monitor the growth of the lichen over time, ensuring proper moisture and humidity levels.
Watering Needs for Parmotrema internexum (Nyl.) Hale
Since Parmotrema internexum is adapted to moist environments, sufficient moisture is essential for its healthy growth. However, overwatering can also cause damage to the lichen. Therefore, you should aim to keep the substrate consistently moist but not waterlogged.
- Water your Parmotrema internexum container gently and sparingly with a spray bottle to avoid overwatering and causing water droplets to damage the lichen.
- Do not allow the substrate to become completely dry, as this can cause the lichen to die.
- Always use non-chlorinated water to avoid toxicity to the lichen.
Fertilization and Soil Requirements for Parmotrema internexum (Nyl.) Hale
Unlike other plants, lichens do not require soil nutrients to grow. Instead, they obtain their nutrients from the air, rainwater, and other environmental sources. Therefore, avoid fertilizing the substrate when cultivating Parmotrema internexum to prevent damage to the lichen.
Pruning for Parmotrema internexum (Nyl.) Hale
Since Parmotrema internexum does not grow roots in soil, pruning is not required. However, you can trim any discolored or dead parts of the lichen as needed to maintain its appearance and prevent further damage. Use sterilized scissors or clippers to avoid introducing any disease-causing pathogens.
Propagation of Parmotrema internexum
Parmotrema internexum is a foliose lichen species that can be propagated through vegetative fragmentation or soredia.
Vegetative Fragmentation
Vegetative fragmentation is a simple method used to propagate Parmotrema internexum. The process involves taking a part of the lichen's thallus and then attaching it to a suitable substrate. The propagule will soon establish itself and propagate to form a new thallus over time.
For vegetative propagation, select a healthy part of the thallus and then detach it gently from the rest of the thallus. Choose a suitable substrate that will serve as the lichen's attachment point, such as a tree bark or rock surface. Ensure that the substrate is clean and free of any contaminants that may impede the lichen's growth.
Once the substrate is ready, attach the lichen to it by gently pressing the propagule onto the substrate and then securing it in place. Water the propagule and maintain a humid environment to facilitate rapid establishment and growth.
Soredia
Soredia are small reproductive structures produced by Parmotrema internexum that can be used to propagate the species. Soredia are powdery or granular in appearance and contain both algal and fungal cells that are capable of forming a new thallus.
To propagate the lichen through soredia, collect mature thalli that have produced soredia. Place the lichen on a sheet of paper and shake lightly to release the soredia from the thallus. The soredia can then be spread out across a suitable substrate for attachment and establishment.
Ensure that the substrate is clean, free of any contaminants, and moist to facilitate soredia attachment and growth. Maintain a humid environment as the soredia establish to ensure proper thallus formation over time.
Disease Management for Parmotrema Internexum (Nyl.) Hale
Parmotrema Internexum is a type of lichen that is relatively hardy and disease-resistant. However, if environmental conditions are not met, diseases may arise. One of the most common diseases affecting this plant is Lichen physci.
To manage Lichen physci, it is important to maintain proper environmental conditions, including adequate sunlight, moisture, and humidity. Additionally, controlling pests and removing any diseased or damaged plant particles can help prevent the spread of this disease.
Pest Management for Parmotrema Internexum (Nyl.) Hale
While Parmotrema Internexum is resistant to most pests, certain insects may still cause damage to the plant. One of the most common pests affecting this plant is the spider mite.
To manage spider mite infestations, it is important to remove any debris or dust that may accumulate on the plant. Regularly spraying the plant with water can also help deter spider mites. Additionally, introducing natural predators, such as ladybugs, can help control spider mite populations.
Another common pest affecting Parmotrema Internexum is the mealybug. To manage mealybug infestations, it is important to keep the plant clean of any debris, and regularly remove any diseased or damaged plant particles. Pesticides may also be necessary to control severe infestations.
