Origin
The plant Lecidea atrobrunnea (Raymond ex Lam. & DC.) Schaerer is a species of lichen that belongs to the family Lecideaceae. It is native to Europe and North America and is commonly found in rocky areas, including cliff faces, boulder fields, and rock outcrops.
Common Names
Lecidea atrobrunnea is commonly known as the dark brown rim-lichen, black-edged rim-lichen, or black-edged lichen. Its scientific name is derived from the Greek words lekithos, meaning "oil," and edios, meaning "form," referring to the oily-looking surface of the thallus, which is the main body of the lichen.
Uses
Lecidea atrobrunnea has no known medicinal or commercial uses. However, it is often used by scientists as an indicator species to monitor air pollution, as it is sensitive to nitrogen dioxide and sulfur dioxide emissions. It is also sometimes used by naturalists as a bioindicator of ecological health, as its presence indicates clean air and good water quality.
General Appearance
Lecidea atrobrunnea has a black or dark-brown thallus, which is thin and crusty, and can reach up to 3 cm in diameter. It is usually visible in small patches on rocks or boulders, and the edges of the thallus are often raised and black or brown in color, especially when young. The apothecia, which are the reproductive structures of the lichen, are black or brown and often have a raised rim that is lighter in color. The lichen is generally inconspicuous, and its small size and dark color help it blend in with its surroundings.
Light Requirements
Lecidea atrobrunnea typically grows in environments with moderate to low levels of light. This species usually prefers shaded areas, but can tolerate exposure to indirect sunlight.
Temperature Requirements
The growth of Lecidea atrobrunnea is highly sensitive to temperature variations. This species usually thrives in environments with mild temperatures and high humidity. Optimal growth conditions range between 15°C and 20°C, with a maximum temperature of 30°C and a minimum temperature of 5°C.
Soil Requirements
Lecidea atrobrunnea seems to be highly adaptable to different soil types, although it prefers well-drained and nutrient-rich substrates. This species is commonly found growing in soil with high organic matter content and neutral to slightly acidic pH levels. It can also grow on rocks and among mosses and lichens.
Cultivation Methods for Lecidea atrobrunnea
Lecidea atrobrunnea belongs to the group of lichenized fungi, and as such, it has different cultivation methods when compared to regular plants. In the wild, it grows on various substrates like trees, rocks, and soil. Therefore, it is possible to cultivate Lecidea atrobrunnea by mimicking the natural environment that it prefers. You can use a substrate like bark or a rock to grow the plant on. The substrates should be dry and kept in a well-ventilated area.
Watering Needs for Lecidea atrobrunnea
Lecidea atrobrunnea is a lichen that can tolerate dry conditions. Therefore, it does not need frequent watering. However, it can benefit from occasional misting or spraying to provide some moisture to the thallus. This is especially important in drier climates. Avoid overwatering as it can lead to the decay of the fungus and ultimately the plant's death.
Fertilization for Lecidea atrobrunnea
As a lichen, Lecidea atrobrunnea obtains its nutrients from the air and the substrate on which it grows. Therefore, fertilization is not necessary, and in fact, it can be detrimental to the plant's health. Fertilizers can lead to the accumulation of salts and other minerals that are toxic to lichens like Lecidea atrobrunnea. So, it is best to avoid fertilizing this plant.
Pruning for Lecidea atrobrunnea
Unlike regular plants, Lecidea atrobrunnea does not need pruning. It has a slow growth rate and does not produce flowers or fruit that require maintenance. However, it is important to keep the substrate on which the plant grows clean and free of debris. This will help ensure that the lichen has access to air, sunlight, and moisture, which are essential for its survival.
Propagation of Lecidea Atrobrunnea
Lecidea atrobrunnea, commonly known as 'black-brown rim-lichen,' is a species of lichen that grows on soil, sand, and rocks. Lichen can propagate sexually or asexually; Lecidea atrobrunnea can propagate by both means.
Asexual Propagation
Asexual propagation of Lecidea atrobrunnea occurs through soredia. Soredia are small, dust-like clusters of algal cells that are derived from the thallus' outer layers. They disperse and develop into new lichens when they fall on a suitable substrate.
The propagation of Lecidea atrobrunnea through soredia is a rapid process. When growing conditions are favorable, the soredia can proliferate quickly. As these structures do not contain the same genetic material as the parent lichen, an identical clone of the parent will not be produced. Instead, the progeny will have some variations from the parent lichen.
Sexual Propagation
The sexual reproduction of Lecidea atrobrunnea occurs through the production of spores; these are called ascospores. Sexual reproduction can result in more significant genetic variation among the progeny than asexual reproduction.
During sexual propagation, the ascospores are produced in the apothecia, which are small round structures that grow from the lichen thallus. The ascospores are released into the environment and can take months to years to germinate, given suitable growth conditions. If conditions are favorable, the apothecia will mature, and new lichen colony growth will begin.
Propagation of Lecidea atrobrunnea through sexual means is a comparatively slower process than asexual propagation. Therefore, this method may not always be advantageous for commercial or personal propagation of the lichen.
Disease Management
Lecidea atrobrunnea is generally a healthy plant and does not suffer from many diseases. However, in some cases, it can be affected by fungal diseases such as leaf spot and powdery mildew.
Leaf spot: The symptoms of this disease include circular or irregular-shaped spots on the leaves. These spots may be brown or black and can eventually lead to defoliation. To manage this disease, it is important to remove and destroy the infected leaves immediately to prevent the spread of the disease. Fungicides can also be applied to control the disease.
Powdery mildew: This disease causes a white or grayish powdery coating on the leaves, stems, and buds of the plant. It can weaken the plant and reduce its growth. To manage powdery mildew, it is essential to maintain good air circulation around the plant and to avoid watering it from the top. Fungicides can also be used to control the disease.
Pest Management
Some pests that may affect Lecidea atrobrunnea include spider mites and mealybugs.
Spider mites: These are tiny pests that feed on the leaves of the plant and can cause yellowing and distortion of the foliage. To manage spider mites, it is important to maintain good humidity levels around the plant and to avoid over-fertilizing it. Insecticidal soap and neem oil can also be used to control the pests.
Mealybugs: These pests are small, white insects that secrete a sticky substance and can cause leaf drop. To manage mealybugs, it is important to isolate the infected plants and to treat them with insecticidal soap or neem oil. Some predators such as ladybugs and lacewings can also be used to control the pests.
