Origin and Common Names
Physcia orbicularis (Necker) Poetsch is a lichen species in the family Physciaceae. It is widely distributed throughout Europe, Asia, and North America. Common names for this lichen include Button Lichen, Lumpy Physcia, and Puckered Physcia.
General Appearance
Physcia orbicularis has a foliose, or leafy, thallus that grows up to 15 centimeters wide. The lobes of the thallus are irregularly shaped and often have rounded edges, giving the lichen its distinctive puckered appearance. The upper surface of the thallus is usually gray or greenish-gray, while the underside is often lighter in color. The apothecia, or fruiting bodies, are small and black and can be found scattered throughout the thallus.
Uses
Physcia orbicularis has no known medicinal or culinary uses. However, it is often used as an indicator of air pollution levels, as it is sensitive to sulfur dioxide and other pollutants. The presence of this lichen in an area is generally considered a sign of good air quality.
Light Requirements
Physcia orbicularis prefers moderate shade to full sunlight exposure. It is commonly found growing on the bark of trees, rocks, and soil surfaces in shaded or partially shaded areas. When exposed to direct sunlight for extended periods, the lichen can become bleached or damaged. Therefore, it is recommended to provide shaded areas when cultivating the lichen.
Temperature Requirements
Physcia orbicularis is a cold-tolerant lichen, growing in temperate to subarctic regions. It can withstand below-freezing temperatures and can survive in areas with a minimum temperature of -20°C. However, it has a maximum temperature tolerance of 25°C, and above this temperature, the growth rate decreases significantly.
Soil Requirements
Physcia orbicularis is not a soil-dependent lichen and is commonly found growing on various substrates. However, it is advisable to provide a substrate that is slightly moist and containing minerals that promote growth. This can be achieved by adding organic matter to the soil surface or by including natural rocks or pebbles in the growing area.
Cultivation of Physcia orbicularis
The cultivation of Physcia orbicularis is not a simple process as this lichen species thrives in its natural environment and grows abundantly on trees and rocks.
However, for cultivation purposes, it is recommended to take healthy specimens from the natural habitat and transfer them to a suitable medium or substrate, such as sterilized peat or soil mixed with sterilized sand.
The substrate should be kept moist and placed in a location that receives bright, indirect light.
Watering Needs
Physcia orbicularis requires a humid environment to grow. The substrate should be kept moist but not too wet, as excessive moisture can lead to fungal growth and decay.
It is therefore important to water the substrate regularly and ensure that it stays moist throughout the cultivation process.
Fertilization
Fertilizers are not necessary for the cultivation of Physcia orbicularis, as the species obtains its nutrients from the air and substrate.
However, if growth seems slow or stunted, a light application of a complete fertilizer designed for use with lichens may be applied.
Pruning
Pruning is not necessary for Physcia orbicularis, as this lichen species generally does not grow beyond the substrate.
However, if it appears to be encroaching on other plants or surfaces, it can be easily removed by hand or with a soft brush.
Propagation of Physcia orbicularis
Physcia orbicularis is a crustose lichen that reproduces both sexually and asexually. The lichen is commonly found in woodlands and forests growing on trees, rocks, and bark. Propagation of this lichen can be done through two methods:
Asexual Propagation
Asexual propagation of Physcia orbicularis is done through fragmentation. The lichen thallus is broken into smaller pieces, which then grow into new lichen individuals. The fragments should contain both the fungal and algal components of the lichen thallus. Once the fragmentation is done, the fragments should be attached to a suitable substrate where they can grow.
Sexual Propagation
Sexual propagation of Physcia orbicularis involves the formation of apothecia, which is the reproductive structure of the lichen. The apothecia produces ascospores that are disseminated by wind or rain to new substrates where they can germinate. Once the spores have germinated, they may form new lichen individuals. For sexual propagation to be successful, the fungal component of the lichen must form a symbiotic relationship with a suitable algal partner.
Disease and Pest Management for Physcia Orbicularis (Necker) Poetsch
Physcia orbicularis is a lichen species commonly found on bark, rocks, and soil across Europe. Like any other living organism, this lichen is susceptible to various pests and diseases. In this section, we will discuss the common diseases and pests that might affect the plant and suggest ways to manage them for optimal growth and health.
Common Diseases
One common disease that affects Physcia orbicularis is blackening or darkening of the thallus. This may happen due to excessive pollution and exposure to chemicals, as well as high humidity levels and poor air circulation. To avoid this, it is best to grow the plant in an area with good air circulation, away from air pollutants. Also, avoid using chemical sprays around the plant.
Another disease that may affect the plant is lichen deteriorations, where the thallus disintegrates, causing the plant to die. This is due to adverse environmental conditions. To prevent this, ensure the plant is in optimal growing conditions, such as adequate light, temperature, and humidity.
Common Pests
Physcia orbicularis is susceptible to various pest infestations. One common pest is mites, which attack the thallus, causing small brown spots and eventual death of the plant. To manage this infestation, use a suitable insecticide to kill the mites and reduce the damage they cause.
Another common pest is snails and slugs, which feed on the thallus, causing holes and deformities. To manage this pest, use snail and slug baits or handpick to remove them from the plant.
In conclusion, preventing diseases and pests from infesting and damaging Physcia orbicularis requires good growing conditions, adequate air circulation, and reducing exposure to pollutants. Timely detection of infestations can help prevent damage and promote optimal plant growth. Taking proper steps to manage diseases and pests when detected can help maintain plant health and ensure optimal yield.
