Placynthium subnigrum de Lesd.
Placynthium subnigrum de Lesd. is a type of lichen that belongs to the family Placynthiaceae. It is commonly known as black button lichen and can be found growing on damp rocks, soil, or tree trunks in temperate regions.
General Appearance
The thallus of Placynthium subnigrum de Lesd. is small and button-shaped, with a diameter of approximately 1 cm. It is characterized by its deep, glossy black color, which is attributed to the production of a pigment called melanin. The surface of the thallus is smooth and shiny, and it lacks any distinct protrusions or lobes.
Common Names
Placynthium subnigrum de Lesd. is commonly known as black button lichen in English. In Spanish, it is referred to as líquen botón negro, while in French, it is known as le placynthium noirâtre.
Uses
Like most lichens, Placynthium subnigrum de Lesd. is not known to have any significant medicinal or culinary uses. However, it is sometimes used as an indicator species to monitor air quality in urban areas due to its sensitivity to air pollution. It is also considered a valuable component of ecological systems, providing a habitat for various microorganisms and serving as a food source for some small animals.
Light Requirements
Placynthium subnigrum de Lesd. is a shade-loving plant that can tolerate low to medium light levels. It is generally found growing in shaded areas such as the forest floor, under tree canopies, or in crevices of damp rocks where direct sunlight is limited.
Temperature Requirements
This plant species is adapted to grow in a cool and humid environment. The ideal temperature range for Placynthium subnigrum is between 10°C to 20°C. It can tolerate occasional temperature fluctuations but prolonged exposure to high temperatures can cause damage to the plant.
Soil Requirements
Placynthium subnigrum prefers to grow in moist and well-draining soil. It is usually found growing in rocky or sandy soil that is rich in organic matter which provides essential nutrients for the plant’s growth. The ideal soil pH range for this plant is between 5.5 to 7.5.
Cultivation Methods
Placynthium subnigrum de Lesd. is a small umbilicate lichen that grows on rocks and is indigenous to Europe. Cultivating this plant may be challenging due to its specific habitat requirements. It is best to grow this plant in an open-air spot, allowing for direct sunlight to aid in photosynthesis.
Watering Needs
The lichen is well adapted to surviving in areas with low moisture, so it does not require frequent watering. Avoid watering the plant too often as it may cause the plant to rot or become diseased. It is best to keep the plant dry, and occasionally mist it to simulate a moist environment.
Fertilization
As a plant that thrives on rocks, Placynthium subnigrum de Lesd. is not dependent on fertilization to grow and survive. Excess nutrients can result in an imbalance that the lichen cannot tolerate, leading to disease and death. Therefore, it is not advisable to use fertilizers.
Pruning
Pruning is unnecessary, and in fact harmful, for the survival of Placynthium subnigrum de Lesd. The lichen survives on photosynthesis from sunlight and does not require leaves or branches. Therefore, it would be best to leave the plant undisturbed and allow nature to take its course.
Propagation of Placynthium subnigrum de Lesd.
Placynthium subnigrum de Lesd. can be propagated through various methods including spore propagation, vegetative propagation, division, and cuttings.
Spore propagation
Spore propagation involves collecting mature spores from the underside of mature fronds and sowing them onto a suitable substrate. The substrate should be kept moist and warm until the spores germinate and develop into young plants. This method requires patience and close attention to detail as spore propagation can be quite challenging.
Vegetative propagation
Vegetative propagation involves using a part of a mature plant to grow a new one. This can be done through stem cuttings, rhizome division, or leaf cuttings. Stem cuttings can be taken from the main stem of the plant, ensuring that there are a few nodes on the cutting. The cutting can be planted in a suitable substrate and kept moist until new roots develop.
Division
Division involves separating a mature plant into smaller parts, each of which can grow into a new plant. This method is suitable for plants with rhizomes or bulbs. The rhizomes or bulbs can be carefully separated from the parent plant and planted in a suitable substrate where they will develop into mature plants.
Cuttings
Cuttings can be taken from a mature plant and used to grow a new one. This method involves taking a section of stem with a few nodes and planting it in a suitable substrate. The substrate should be kept moist and warm until new roots develop and the cutting grows into a mature plant.
Disease Management
Placynthium subnigrum de Lesd. is susceptible to a few fungal diseases, including foliar diseases caused by species of Mycosphaerella and Phoma. These diseases can affect the leaves, causing yellowing, wilting, and premature leaf drop. To manage these diseases, ensure you keep the plant clean and free of debris. Appropriate pruning and sanitation practices can help reduce the spread of these diseases. Fungicides may also be useful in controlling these diseases, but be sure to follow the instructions on the label for better results.
Pest Management
Placynthium subnigrum de Lesd. is susceptible to insect pests, including aphids and spider mites. Aphids are small, sap-sucking insects that can cause stunted growth and deformity of the plant. Spider mites, on the other hand, are tiny arachnids that can cause yellowing and mottled leaves. To manage these pests, regular inspection of the plant is necessary. Early detection of these pests can help prevent their spread. Consider using insecticidal soaps, horticultural oils, or neem oil to control these pests. Introducing pest predators like ladybugs can also be effective in controlling aphids and other insects.
