Pertusaria lecanina Tuck. - General Overview
Pertusaria lecanina Tuck. is a lichenized fungus belonging to the family Pertusariaceae, which is commonly found on tree bark, rocks, and soil in temperate and boreal regions all over the world. This species is also known by common names such as Lecanine saucer lichen, Flat saucer lichen, and Pimpled shadow lichen.
General Appearance
Pertusaria lecanina Tuck. forms crustose thalli, ranging from pale to dark-grey in color, that are usually around 2-6 cm in diameter. The thalli are somewhat raised and contain numerous black, convex apothecia that range in size from 0.2-1 mm in diameter.
Uses
Pertusaria lecanina Tuck. has little known commercial uses, but it is often used in scientific studies and as a bioindicator of air pollution. These lichens can absorb heavy metals and other pollutants from the atmosphere, making them valuable tools in monitoring air quality.
Additionally, historically, some cultures have used certain species of lichens, including Pertusaria lecanina Tuck., for medicinal purposes such as treating headaches and stomach issues. However, it is essential to recognize that the use of lichens for medicinal purposes is not supported by modern medicine and that some species may be toxic if ingested.
Light Requirements
The plant Pertusaria lecanina Tuck. prefers moderate to high levels of light. It can grow in partial sunlight or shaded areas, but growth and development will be slower and may result in limited fruiting. On the other hand, excessive exposure to direct sunlight may result in desiccation and leaf damage. For optimal growth, it is recommended to provide the plant with around 6-8 hours of sunlight per day.
Temperature Requirements
The ideal temperature range for Pertusaria lecanina Tuck. growth is between 20 to 25°C (68 to 77°F). It can tolerate higher temperatures up to 30°C (86°F), but prolonged exposure may lead to heat stress and reduced growth. The plant is also sensitive to freezing temperatures, which can damage the leaves and inhibit growth. In cooler climates, the plant can thrive indoors or under controlled greenhouse conditions.
Soil Requirements
The plant Pertusaria lecanina Tuck. prefers well-draining, nutrient-rich soil that is slightly acidic to neutral (pH 6.0 to 7.0). It can grow in a variety of soil types, including sandy, loamy, or clayey soils. However, the soil must be properly aerated and should not be waterlogged, as excess moisture can lead to root rot and other fungal diseases. It is recommended to amend the soil with organic matter such as compost or leaf litter to improve soil structure and provide essential nutrients for plant growth.
Cultivation
Pertusaria lecanina Tuck. is an epiphytic lichen that grows on tree trunks, branches, and twigs. To cultivate it, you will need to find a tree with the right bark and habitat conditions. Look for trees that are in good health, have rough and fairly thin bark, and get plenty of indirect sunlight. Oaks, maples, and birches are some of the trees that are most suitable for cultivating Pertusaria lecanina Tuck. Lichen colonies are often specialized in their substrate preferences, so it’s best to collect a small sample to check if it’s compatible with your tree specimen before starting a new colony.
Watering needs
Pertusaria lecanina Tuck. does not have any roots, so it absorbs water and nutrients directly from the air and the bark of the host tree. The amount of moisture this lichen needs depends heavily on local climate conditions, humidity, and rainfall. In general, lichens thrive in damp environments, and they can absorb a lot of water when mist and dew are present. It is important to ensure that the lichen colony is not subjected to prolonged drought, but it is also essential not to overwater as this can cause the lichen to detach from the bark.
Fertilization
Since Pertusaria lecanina Tuck. is a lichen that relies on photosynthesis to produce food, it doesn’t require any type of fertilizer. In fact, chemical fertilizers could harm the lichen if applied directly to it. However, it is important to ensure that the tree where it is growing is healthy and not exposed to any chemical toxins that could damage the lichen.
Pruning
As an epiphytic lichen, Pertusaria lecanina Tuck. doesn’t require any pruning. If your colony has grown too big and you want to reduce its size, you can carefully remove some of the outer edges with a pair of scissors or shears. However, keep in mind that lichens develop very slowly and it may take years for the colony to recover and regain its original size and shape.
Propagation of Pertusaria lecanina Tuck.
Pertusaria lecanina Tuck. can be propagated by two primary methods: vegetative propagation and spore propagation.
Vegetative Propagation
Vegetative propagation method involves separating a mature piece of a plant and transferring it to a new medium for growth. This method can be used for Pertusaria lecanina Tuck. by taking mature lichens and cutting them into smaller pieces, which can be transplanted to new surfaces like tree bark or rocks. The pieces should be kept in a humid environment and monitored closely to prevent dehydration until they establish new attachments and begin to grow.
Spore Propagation
Spore propagation method involves harvesting and cultivating the lichen's spore cells to generate new individuals. For Propagation of Pertusaria lecanina Tuck., the process includes finding mature lichens that contain reproductive organs, upon which spores have developed. The lichen can be placed in a plastic bag and kept warm and moist to release the spores. The spores collected can then be placed in a culture medium like PD agar or potato dextrose. The medium is then incubated under controlled conditions like temperature and light for the growth of new individuals.
Once the new plants have grown, they can be transferred to the desired growing environment after reaching maturity. Additionally, it is important to maintain an appropriate growing environment for both propagation processes, which involves a suitable temperature, humidity, and light environment.
Disease and Pest Management for Pertusaria lecanina Tuck.
Pertusaria lecanina Tuck., commonly known as shield lichen, is a species of lichen that is relatively resistant to most diseases and pests. However, its health can still be affected if the growing conditions are not optimal, leading to the development of various lichen diseases and attacks by various pests that have learned to feed on the shield lichen.
Common Diseases
The most common disease that affects Pertusaria lecanina is lichen fragmentation due to environmental factors such as disturbances, pollution, or natural processes. To avoid fragmentation, it is important to limit disturbances and ensure that the growing conditions are kept optimal. Additionally, some species of fungi also infect Pertusaria lecanina, causing blight and discoloration. These fungi can be controlled by removing the infected parts and applying a fungicide to protect the healthy parts.
Common Pests
While Pertusaria lecanina is relatively pest-resistant, some organisms have evolved to feed on the shield lichen. Some common pests that attack Pertusaria lecanina include slugs, snails, and insects. To control the pests, one can use natural predators, like birds and beneficial insects, or take steps to discourage the pests, like utilizing copper-based fungicides or molluscicides for snails and slugs. Additionally, one can also hand-pick snails and slugs or use traps to capture the pests.
Conclusion
To keep Pertusaria lecanina healthy, it is important to maintain optimal growing conditions and to remain vigilant for signs of disease or pests. Any signs of distress should be immediately addressed, utilizing appropriate disease or pest control measures. As with any plant, preventative measures are key to maintaining the health of Pertusaria lecanina, including regular maintenance, monitoring, and careful attention to environmental conditions.
