Overview
Rhizocarpon umbilicatum (Ramond) Flagey, commonly known as the navel lichen, is a species of lichen that belongs to the Rhizocarpon genus in the family Rhizocarpaceae. This lichen is found in rocky environments across Europe and North America.
General Appearance
The navel lichen has a distinct appearance that makes it easy to identify. It forms a greenish-grey to yellowish-green crust that grows tightly against rocks, making it hard to remove once established. The thallus ranges from thin to thick, with the surface consisting of small, round-lobed areoles. The center of each areole has a concave depression referred to as the umbilicus, thus the name "navel" lichen.
Uses
The navel lichen is not known to have any practical uses for human consumption. In traditional European medicine, lichens such as R. umbilicatum were used to treat minor ailments such as coughs and colds. However, caution is advised when consuming lichens as they can contain toxins. Navel lichens are known to absorb pollutants from their environment, so they have been used as bioindicators of air quality. Additionally, the species is an important component of some ecosystems and provides habitat and shelter for microorganisms and insects.
Origin
The navel lichen is native to many parts of Europe and North America. It prefers habitats with exposed rocks, such as alpine regions and cliffs in temperate forests. The lichen is cold-tolerant, so it thrives in high-altitude environments. The species is thought to be widespread and not threatened, but some populations have been affected by pollution, habitat degradation, and climate change.
Light Requirements
Rhizocarpon umbilicatum is a lichen that is found in a range of light conditions. The plant can tolerate low and bright light levels, but it grows the best in moderate light conditions. In areas with high light intensity, the lichen may appear dark and show signs of stress. On the other hand, in low light conditions, it may develop slowly, and its thalli may become thin and elongated.
Temperature Requirements
The growth of Rhizocarpon umbilicatum is highly dependent on temperature. For optimal growth, the plant requires a cool to moderate temperature range of 10 to 20°C. High temperatures above 25°C can hinder growth, and prolonged exposure may lead to cellular damage. In addition, low temperatures can also affect growth, such that temperatures below 0°C can inhibit growth, and the lichen may become dormant until the temperature rises again.
Soil and Substrate Requirements
Rhizocarpon umbilicatum is a crustose lichen that is often found growing on rocks, gravels, and soils. The plant grows well in well-drained soils that are slightly acidic to neutral in pH. In addition, it can grow in areas with minimal soil development, and it can colonize heavily disturbed and polluted substrates such as road cuttings and roofs. However, the lichen is intolerant to soils with high levels of salinity and toxic metals such as copper and lead.
Cultivation methods
Rhizocarpon umbilicatum (Ramond) Flagey, commonly known as the umbilicate lichen, is commonly found growing on rocks or boulders in the damp alpine and subalpine areas. It is a slow-growing plant that is highly resistant to climatic conditions and is suitable for cultivation.
The best way to cultivate this plant is by propagating it vegetatively. This can be done by collecting fragments of the plant or by transplanting a small portion of the thallus from its natural habitat.
The plant also requires proper aeration and good drainage. It should be grown in a porous medium, such as a mixture of sand, bark, and peat moss. It should also be grown in a cool environment with moderate sunlight exposure and consistent humidity.
Watering needs
The plant requires frequent watering, especially during the growing season. The soil should not be allowed to dry out but should remain evenly moist. Overwatering should be avoided, as it can promote fungal growth and lead to root rot.
The plant requires a consistent humidity level of around 60% to 80%, which can be achieved by misting the plant regularly. The use of a humidity tray is also recommended.
Fertilization
Rhizocarpon umbilicatum does not require regular fertilization. However, it can benefit from a light application of a slow-release fertilizer once a year during the growing season. Alternatively, a liquid fertilizer can be applied every two to three weeks at half strength.
It is important to note that excessive fertilization can promote the growth of algae or moss and lead to the weakening of the plant.
Pruning
The umbilicate lichen does not require pruning. However, dead or decaying portions of the thallus should be removed to promote healthy growth and prevent the spread of disease.
When pruning, sharp, sterilized tools should be used to prevent damage or infection to the plant.
Propagation of Rhizocarpon umbilicatum
Rhizocarpon umbilicatum (Ramond) Flagey is a lichen species that is commonly found growing on rocks and boulders in mountainous regions. Propagation of this plant species can be done through two methods - vegetative propagation and spore propagation.
Vegetative Propagation
Vegetative propagation involves taking a piece of the plant and encouraging it to grow into a new plant. This method is typically used when the plant is unable to produce spores or when a particular genotype is desired. For Rhizocarpon umbilicatum, vegetative propagation can be done by carefully removing a section of the thallus (the main part of the lichen body) and transferring it to a suitable substrate, such as a rock or a piece of bark. The piece of thallus should be kept moist and in an area with moderate light until new growth appears. Once new growth is observed, the new plant can be transplanted to its permanent home.
Spore Propagation
Spore propagation involves collecting spores from the plant and encouraging them to grow into new individuals. This method is typically used when genetic diversity is desired. For Rhizocarpon umbilicatum, spore propagation can be done by collecting mature apothecia (small reproductive structures) from the plant. The apothecia should be gently crushed to release the spores onto a suitable substrate, such as a piece of wet filter paper. The substrate should be kept moist and in an area with moderate light until the spores begin to germinate. Once germination occurs, the new plants can be transplanted to their permanent home.
Propagation of Rhizocarpon umbilicatum can be a slow process, but with proper care and attention, new plants can be grown successfully.
Disease and Pest Management for Rhizocarpon umbilicatum (Ramond) Flagey
Rhizocarpon umbilicatum (Ramond) Flagey, also known as rock yellow lichen, is a hardy lichen that grows on rocks and soil. It is rarely affected by diseases and pests. However, there are still some common problems that can arise which can be managed effectively with proper care and attention. Here are some of the diseases and pests to watch out for and manage:
Diseases
One of the most common diseases that can affect Rhizocarpon umbilicatum is lichen necrosis. This condition can occur when the lichen is under stress due to adverse environmental conditions such as air pollution or heavy rainfall. To manage this disease, it is essential to keep the growing environment as balanced as possible.
Another disease that can affect this lichen is powdery mildew. Powdery mildew occurs when there is a fungal infection, and it can be identified by white patches on the surface of the lichen. To manage this condition, remove the infected sections and keep the growing environment dry since this condition thrives in humid conditions.
Pests
The most common pests that can affect this lichen are snails and slugs, which can eat away the thallus or the fruiting bodies of the lichen. This can significantly decrease the lichen's lifespan. To prevent this, regularly check the growing area for these pests and remove any that you find by hand.
Another pest that can damage the lichen is the bird cherry ermine moth, which can feed on the leaves of the lichen. To manage this, use insecticides that are safe for use on lichens or manually remove the larvae as soon as they appear.
To keep your Rhizocarpon umbilicatum healthy and free from diseases and pests, it is crucial to maintain a clean growing environment, provide adequate airflow, and avoid overcrowding. With proper care, you can enjoy the beauty and benefits of this hardy lichen for many years to come.
