General Description
Lecanora brouardii (de Lesd.) is a species of lichen commonly found in the Saint Lawrence River Valley and the Great Lakes region in North America. It belongs to the family Lecanoraceae and the genus Lecanora. This lichen is also known by several common names such as Brouard's rim-lichen, eared rim-lichen, or simply, eared lichen.
Appearance and Characteristics
Lecanora brouardii is a foliose lichen that features a thallus with a grey-green to brownish color and a large number of small lobes, standing out from its dark-colored rim. Its lobe edges have a rounded to wavy appearance and even have some small ear-like extensions hence its common name, eared rim-lichen. The surfaces of the lobe are flat or slightly convex and marked by tiny pin-like projections that are ostioles.
This lichen is typically found growing on the surface of rocks, tree trunks, and even soil.
Uses
Lecanora brouardii is known to be a bioindicator of air pollution in the areas where it grows. This property is so useful that it is incorporated in some environmental monitoring programs. Additionally, extractives from Lecanora brouardii have shown to possess anti-inflammatory properties, making it a potential source of medicinal compounds.
The lichen is also edible, and it is commonly used in traditional ethnobotanical medicines of the Ojibwe people of North America to treat colds and fever.
Light Requirements
Lecanora brouardii is a crustose lichen that prefers growing in bright light. It can tolerate moderately shady conditions, but usually, it grows in open areas where it can be exposed to direct sunlight.
Temperature Requirements
The ideal temperature range for the growth of Lecanora brouardii is between 5°C and 25°C. However, it can survive in temperatures as low as -15°C for short periods of time. Extreme temperatures above 30°C can cause dehydration and death of the lichen.
Soil Requirements
Lecanora brouardii grows mainly on calcareous rocks, concrete, and walls. It can also grow on soil, but it prefers well-drained substrates. The pH of the substrate should be alkaline to slightly acidic, with pH values between 6 and 8.5.
Cultivation methods for Lecanora brouardii
Lecanora brouardii is a lichen that grows on soil, rocks, and trees in the Mediterranean region. To cultivate Lecanora brouardii, collect the thalli or small pieces of the lichen and bring them home to start the process.
The first thing to do is to sterilize the substrate, which can be sand or a mixture of sand and peat. Once the substrate is sterilized, place the thalli on it and keep it in a moist environment. The substrate needs to be damp but not soaking wet. Spray it with water regularly to keep it moist but avoid overwatering to prevent waterlogging.
Place the container in a well-lit area but avoid direct sunlight. The ideal temperatures for Lecanora brouardii growth range between 15°C to 25°C. With proper care and maintenance, the lichen will gradually colonize the substrate, and after several months, mature thalli will develop.
Watering needs for Lecanora brouardii
Watering is a crucial aspect of Lecanora brouardii cultivation. The lichen requires sufficient moisture to thrive, but too much water can be detrimental. Overwatering can lead to waterlogging, which can cause root rot and ultimately kill the lichen.
Water once or twice a week, depending on the humidity levels. Use a spray bottle to mist the thalli and substrate to keep them slightly damp. Ensure that the container has drainage holes to prevent water accumulation.
Fertilization for Lecanora brouardii
Unlike other plants, Lecanora brouardii does not require fertilization. The lichen gets all its nutrients from the air, and topdressing it with fertilizer can harm it. It is, therefore, vital to maintain a balanced ecosystem around the lichen's cultivation zone to ensure its survival.
Pruning for Lecanora brouardii
Lecanora brouardii does not require pruning. The lichen grows naturally and does not develop shoots or branches that require trimming. The only care it needs is to remove any dead thalli or debris around the substrate. This ensures that there is no buildup of harmful microorganisms or pests in the lichen's vicinity.
Propagation of Lecanora brouardii
Lecanora brouardii (de Lesd.) is mainly propagated through the dispersal of its reproductive structures. These structures are known as apothecia, which are disk-shaped fruiting bodies that contain the spores of the lichen.
Vegetative Propagation
Vegetative propagation of Lecanora brouardii can occur through fragmentation. When a portion of the lichen thallus breaks off, it can potentially colonize a new substrate, forming a new lichen colony.
Dispersal of Apothecia
Dispersal of apothecia is the primary method of reproduction for Lecanora brouardii. When the spores inside the apothecia are released, they can potentially establish new colonies on substrates that are hospitable to the lichen. However, successful establishment is highly dependent on the availability of suitable habitats and the presence of compatible algal partners.
Disease and Pest Management for Lecanora brouardii
Lecanora brouardii, commonly known as rock gray lichen, is a crustose lichen found in rocky habitats. While this lichen does not have many known pests or diseases, there are some that can affect its growth and survival. Here are the common diseases and pests that might affect Lecanora brouardii and some ways to manage them.
Common Diseases
One of the most common diseases that affect Lecanora brouardii is black fungus. This fungal disease can cause the lichen to turn black and become brittle. Black fungus is often a sign of poor air quality, stress, or environmental pollution. To manage this disease, it is essential to improve air quality and reduce pollution in the area where the lichen is growing.
Another common disease that can affect Lecanora brouardii is lichenicolous fungi. These fungi can grow on the lichen's surface, reducing its photosynthetic abilities and weakening its structure. To manage this disease, remove any visible patches of lichenicolous fungi and improve the lichen's growing environment by controlling its moisture levels and increasing light exposure.
Common Pests
While Lecanora brouardii is not a food source for many pests, some insects and animals may consume it. For example, small rodents, such as mice, may eat the lichen to supplement their diet. To manage these pests, use barriers or traps to prevent them from accessing the lichen. Additionally, avoid using harmful chemicals or pesticides that may harm the lichen or its environment.
In conclusion, being aware of the common pests and diseases that may affect Lecanora brouardii is essential for its management. Implementing necessary measures to manage these issues, such as improving air quality, reducing pollution, and controlling moisture levels, will help maintain the lichen's health and increase its survival rate.
