Origin and Common Names
Rhizocarpon polycarpum (Hepp.) Th. Fr. is a species of lichen that is commonly found in arctic and alpine regions worldwide. It is commonly known as the Many-fruited Rhizocarpon lichen.
Appearance
The thallus of Rhizocarpon polycarpum is crustose and forms a tight relationship with its substratum. It appears as small, round, or irregular-shaped patches with a diameter of about 1-2 cm. The color of thallus ranges from rosy-orange to bright yellow-green. Its surface is covered with numerous small, convex, and dark-red apothecia that range from .5-1.5 mm in diameter. Its apothecia contain numerous spores with one or two cells.
Uses
Rhizocarpon polycarpum has no known uses in modern medicine. However, it plays a crucial role in the Arctic ecosystem by serving as a food source for several animals such as lemmings and reindeer. It also contributes to soil formation and acts as an indicator of environmental changes due to its sensitivity to air pollutants such as sulfur dioxide and nitrogen oxides.
Light Requirements
Rhizocarpon polycarpum (Hepp.) Th. Fr. is an obligately saxicolous lichen that requires exposure to sunlight or diffuse light for photosynthesis. Therefore, it typically grows on open rocky surfaces that receive direct or indirect sunlight.
Temperature Requirements
Rhizocarpon polycarpum (Hepp.) Th. Fr. is found in a wide range of temperatures, from the Arctic to lower elevations in more temperate climates. The optimal temperature for its growth is between 10 to 15 degrees Celsius, with growth slowing above and below this range.
Soil Requirements
Rhizocarpon polycarpum (Hepp.) Th. Fr. is a pioneer lichen species that can grow on a variety of mineral substrates, including siliceous and calcareous rocks. It can grow under different conditions, including acidic or alkaline soils, and can tolerate low nutrient levels. It can also grow on soils with varying moisture contents and water-holding capacities.
Cultivation and Care of Rhizocarpon Polycarpum
Rhizocarpon polycarpum is a lichen that grows on rocks and stones in wild areas such as mountains, and it is not commonly cultivated. However, it can be grown artificially in a controlled environment.
Cultivation Methods
To grow Rhizocarpon polycarpum in a controlled environment, it is firstly necessary to collect healthy specimens from the wild carefully. The lichen can then be propagated by fragmenting the thallus and attaching it to a suitable substrate, such as calcareous rock, using adhesive. The container containing the lichen should be placed in a room with the correct environmental conditions.
The container should be covered with saran wrap to maintain constant humidity. The lichen needs to be kept at a temperature between 10°C and 18°C and at a relative humidity of about 90% to 100%.
Watering Needs
To water Rhizocarpon polycarpum, spray the lichen surface with distilled water and ensure that there is no water accumulation. The lichen should not be allowed to dry out completely, and it should never be watered with tap water since it can be harmful to the lichen.
Fertilization
Artificial fertilization is not necessary for Rhizocarpon polycarpum, as it obtains all the nutrients it needs from its environment. It is, therefore, best to avoid fertilizing it.
Pruning
Since Rhizocarpon polycarpum is a slow-growing lichen that adheres firmly to its substrate, pruning is not required.
Propagation of Rhizocarpon Polycarpum
Rhizocarpon polycarpum is a lichen species that mainly reproduces through vegetative propagation. It usually thrives in rocky habitats, and its propagation is quite different from that of conventional plants.
Vegetative Propagation
Vegetative propagation is the primary method of propagation for Rhizocarpon polycarpum. This occurs when small fragments of the lichen break off from the thallus and establish themselves on new substrates. The lichen status also plays a vital role in vegetative propagation, with young lichens being more prone to fragmentation than mature ones.
The fragments of Rhizocarpon polycarpum are usually small and carried by wind or animals. They can then fall on a new substrate such as rocks, where they reestablish themselves and continue to grow.
Asymbiotic culture
Another propagation method for Rhizocarpon polycarpum is through asymbiotic culture. This method involves growing the mycobionts and photobionts separately in artificial conditions. The mycobionts are grown in pure culture media, while the photobionts are cultured in an artificial substrate. The two are then combined to form a lichen symbiont.
Asymbiotic culture offers a way to study the growth and propagation rate of Rhizocarpon polycarpum under controlled conditions. The method is also suitable for experiments on the growth and physiology of Rhizocarpon polycarpum, as well as for the production of secondary metabolites.
Conclusion
Rhizocarpon polycarpum is a unique plant species that mainly reproduces through vegetative propagation and asymbiotic culture. As a lichen, it requires suitable substrates and conditions to thrive and grow. Understanding these aspects can help in the conservation and production of this valuable species.
Disease and Pest Management for Rhizocarpon polycarpum (Hepp.) Th. Fr.
Rhizocarpon polycarpum (Hepp.) Th. Fr. is a species of lichen commonly found in harsh and dry alpine environments. Despite being a resilient plant, it is not completely immune to disease and pest problems. As a helpful assistant, here are some common diseases and pests that might affect the plant and suggest ways to manage them.
Diseases
Lichen Spot Disease: This is a common fungal disease that affects lichens, including Rhizocarpon polycarpum. It usually appears as small brown spots on the thallus, which eventually lead to the death of the lichen. To manage this disease, avoid overwatering the plant, provide adequate ventilation, and remove any infected parts of the lichen immediately.
Rhizocarpon Causticum: This is another fungal disease that causes the thallus to become watery and yellowish-green, and eventually die. To manage this disease, avoid over-fertilizing the plant and keep the surrounding area clean and free from debris.
Pests
Aphids: These are small insects that feed on plant sap, causing deformities and stunted growth. To manage aphids, blast them off the plant with a strong jet of water or use natural predators such as ladybugs or lacewings to control their population.
Spider Mites: These are tiny pests that suck sap from the plant, causing discoloration and leaf drop. To manage spider mites, keep the plant well-watered, prune infested leaves, and use insecticidal soap or neem oil to control their population.
Overall, maintaining good plant health is the best approach to prevent diseases and pest problems in Rhizocarpon polycarpum. Regular monitoring of the plant, providing optimal growing conditions, and using natural remedies when possible are better than using harsh chemicals that could harm the plant and surrounding environment.
