Origin
Cetraria islandica (L.) Ach. ssp. islandica, also known as Icelandic moss, is a lichen that belongs to the Parmeliaceae family. It is native to the arctic regions of the Northern Hemisphere, including Iceland, Scandinavia, and Siberia.
Common Names
Icelandic moss is also commonly known as grey moss, Iceland lichen, and fjallagrös in Icelandic. It has also been referred to as "forest gold" due to its medicinal properties.
Uses
For centuries, Icelandic moss has been used as a traditional medicine and as a food source. It has been used to treat respiratory problems, digestive issues, and sore throats. The lichen is also rich in Vitamin C and has been used to prevent scurvy. Icelandic moss also has anti-inflammatory properties and can relieve symptoms of coughs and colds. It is commonly used in cough syrups and lozenges.
In addition to its medicinal uses, Icelandic moss has been used as a food source during times of famine. It can be eaten raw or cooked, and provides a source of nutrients such as carbohydrates and minerals.
General Appearance
Icelandic moss is a fruticose lichen. It grows in tufts and forms dense cushions on rocks, soil, and tree bark. The thallus (main body) of the lichen is usually yellowish-grey or brownish-grey, with a branching and flattened appearance. The underside of the thallus is white or cream-colored, and has root-like structures called rhizines that attach to the surface it grows on. The lichen can grow up to 10 cm in length, and can form extensive carpets in areas where it is abundant.
Overall, Icelandic moss is a fascinating and useful plant that has many cultural and medicinal uses in the arctic regions where it is found.
Light Requirements
Cetraria islandica (L.) Ach. ssp. islandica is adapted to moderate light conditions. It grows best in partially shaded areas and can tolerate a few hours of direct sunlight. However, extended exposure to high light intensity can cause damage to the plant's thallus and reduce its growth rate.
Temperature Requirements
Cetraria islandica (L.) Ach. ssp. islandica is a cold-adapted species that can grow in subarctic to arctic regions. The optimum temperature range for its growth is between 5°C and 15°C. The plant can tolerate freezing temperatures and survive under snow cover during winter.
Soil Requirements
Cetraria islandica (L.) Ach. ssp. islandica is a soil-preferring lichen that grows on well-drained and acidic substrates. The plant is commonly found on mineral soil, rocks, and mosses. It does not require nutrient-rich soils but can benefit from occasional fertilization with nitrogen and phosphorus.
Cultivation Methods
Cetraria islandica (L.) Ach. ssp. islandica, commonly known as Icelandic moss, is a lichen species that is native to the Arctic and alpine regions of Europe and North America. The plant prefers to grow on well-drained, acidic soils in shaded areas. The propagation of this plant is mainly through vegetative means as it does not produce flowers or seeds. The best way to cultivate this plant is by transferring it from its natural habitat to the garden or by using pieces of its thalli on which it can grow.
Watering Needs
Cetraria islandica requires adequate moisture to thrive. The plant needs to be kept moist at all times, but not waterlogged. Overwatering can cause the roots to rot, which can kill the plant. It is advised to water the plant about twice a week during the growing season. The water should be carefully poured at the base of the plant to avoid wetting its leaves as this can cause fungal infections.
Fertilization
Cetraria islandica does not require regular fertilization as it obtains its nutrients from the air and the surrounding environment. However, it can be beneficial to add a light application of organic fertilizer to the soil twice a year, preferably during spring and autumn. This helps to promote healthy growth and development of the plant.
Pruning
Cetraria islandica does not require frequent pruning because it grows slowly. However, if it becomes unruly, it can be pruned in the early spring to keep its shape and size in check. Dead or damaged parts of the plant can also be removed as soon as they are noticed to keep the plant healthy.
Propagation of Cetraria islandica (L.) Ach. ssp. islandica
Cetraria islandica (L.) Ach. ssp. islandica, commonly known as Icelandic moss, is a lichen species that can be propagated by four methods:
Division
The easiest method of propagation of Cetraria islandica is by division of the thallus. Division is similar to the process of vegetative propagation where each divided section is capable of growing into a new plant. Simply break off pieces of the lichen and replant them in a new area with similar environmental conditions.
Soredia Propagation
Cetraria islandica species also propagate by releasing soredia that are carried by the wind, water, or animals. The soredia are small outgrowths found on the surface of thallus that contain both algal and fungal partner cells. When the soredia fall off the thallus, they can grow into new lichen colonies if the environmental conditions are suitable.
Fragment Propagation
Another method of propagation for Cetraria islandica is by the fragmentation of the thallus. Fragmentation is a natural process where a part of the thallus undergoes self-disturbance caused by environmental factors like wind, water, or animals. If the fragments are large enough, they can grow into new lichen thalli but this method of propagation is slow due to the need for new attachment to substrates and fungal-algal recombination.
Coralline Propagation
Coralline propagation occurs when coralline structures are produced by the lichen to increase their attachment strength to their substrate. These structures are released and can lead to new colonies of Cetraria islandica. Coralline propagation is often confused with soredia formation because of their outward appearance, but they occur through different mechanisms and are not the same.
Disease Management
Cetraria islandica (L.) Ach. ssp. islandica is susceptible to several fungal diseases, which can lead to significant damage if not managed properly. Here are some of the common diseases and control measures:
Anthracnose
Anthracnose is a fungal disease that causes brown spots to develop on the leaves and stems of Cetraria islandica. It can spread rapidly and cause defoliation if not managed appropriately. The best practices for managing anthracnose include using clean propagation materials, avoiding overhead irrigation, and removing infected plant parts. Fungicides can also be helpful in controlling the disease.
Phytophthora Root Rot
Phytophthora root rot is a soil-borne fungal disease that attacks the roots of Cetraria islandica, causing them to rot and decay. The disease typically manifests itself in yellowing leaves and stunted growth. To manage Phytophthora root rot effectively, you should implement proper drainage, avoid overwatering, and ensure that the plant is not sitting in water. Fungicides can also be used to control the spread of the disease.
Lichen Moth
The lichen moth is an insect that feeds on the foliage of Cetraria islandica, causing defoliation and weakening of the plant. To manage the lichen moth, you should encourage natural predators such as birds and ladybugs in the area and remove any highly infested areas by handpicking the insects. Insecticides can also be used to control the spread of the moth.
Pest Management
Cetraria islandica (L.) Ach. ssp. islandica is susceptible to a few common pests, which can cause significant damage if not managed appropriately. Here are some of the common pests and control measures:
Spider Mites
Spider mites are tiny arachnids that feed on the sap of Cetraria islandica leaves, leading to discoloration and deformation. You can use a forceful stream of water or insecticidal soap to control spider mite populations. Additionally, predatory mites can be introduced to the area as a natural form of control.
Aphids
Aphids are small insects that can cause significant damage to Cetraria islandica by sucking the sap from the leaves and stems, leading to stunted growth and deformation. To control aphids on your plant, use insecticidal soaps or oils to suffocate and kill them. You can also encourage natural predators such as ladybugs and lacewings to feed on the aphids.
Mealybugs
Mealybugs are small white insects that can cluster on Cetraria islandica, causing stunted growth and yellowing of the leaves. You can control mealybug populations by pruning and disposing of heavily-infested areas, introducing natural predators, or applying insecticidal soap or oils.
