Introduction
Melanelia sorediosa (Almb.) Essl. is a lichen species that belongs to the Parmeliaceae family. This lichen is commonly known as tree tar lichen or black tar lichen due to its black color and sticky texture. The fungus and algae of this lichen form a symbiotic relationship that allows it to live in harsh, dry environments.
Origin and Distribution
Melanelia sorediosa is native to North America and can be found growing on the bark of various trees, including conifers and hardwoods. This lichen species can be found in regions such as Alaska, northern Canada, and down into the Rocky Mountains.
Appearance
Melanelia sorediosa is a foliose lichen, meaning it has a leafy appearance and is attached to its substrate by a filament-like structure called a rhizine. The thallus, or vegetative body of the lichen, is made up of dark brown to black lobes that are sometimes imbricate with a warty texture. The thallus can grow up to 10 centimeters in length and is covered with small, black, tar-like, globose soredia which can be used to reproduce and colonize new areas.
Uses
Melanelia sorediosa has been traditionally used by various indigenous groups for medicinal purposes. It is said to have antimicrobial, antifungal, as well as anti-inflammatory properties. It has also been used as a dye for clothing and basketry, due to its deep black pigment.
Light Conditions
Melanelia sorediosa is a shade-tolerant lichen species that can survive in both full sun and partial shade. However, it prefers to grow in partially shaded areas, such as the trunks and branches of trees. Excessive exposure to sunlight can cause the lichen to dry out and die, while too much shade may limit its growth and reproduction.
Temperature Requirements
Melanelia sorediosa is a cold-tolerant species that can grow in a wide range of temperatures. It is commonly found in subalpine and alpine regions, where the temperatures are cool throughout the year. The optimal temperature for its growth and survival is between 5°C to 15°C. However, it can withstand temperatures as low as -20°C and as high as 28°C.
Soil Requirements
Melanelia sorediosa is a lichenized fungus that grows on the bark of trees, rocks, and other substrates. It prefers to grow on the bark of deciduous trees, such as birch, oak, and maple, and also on conifers like spruce and pine. The lichen can tolerate a range of soil pH levels, from acidic to alkaline, but it requires a well-draining substrate. It is sensitive to air pollution and is often used as a bioindicator for environmental quality.
Cultivation Methods of Melanelia Sorediosa
Melanelia sorediosa is a lichen that grows on trees in various habitats such as conifer forests and mountain slopes. Cultivation of this lichen in a home or commercial setting is challenging. However, if you want to cultivate it, the first thing to do is to locate a host tree, preferably conifers. You can place the lichen fragments in a mesh bag and attach it to the trunk of the host tree using a string, wire or plastic ties. Place the mesh bag in a shady and humid location and leave it undisturbed for at least two months.
Watering Needs of Melanelia Sorediosa
Watering Melanelia sorediosa requires a delicate touch since too much water can kill the lichen. It is important to keep the lichen consistently moist, but not wet. Water the lichen with a sprayer or by gently misting it. Ensure to avoid spraying water in excess, which can lead to mortality.
Fertilization for Melanelia Sorediosa
Since Melanelia sorediosa is a lichen, it does not require fertilization. Lichens get the nutrients they need from the air, light and any dust and debris that land on its surface. They can also absorb nutrients from rainwater.
Pruning of Melanelia Sorediosa
Pruning Melanelia sorediosa is not necessary since it is a lichen, and all it needs is a host tree where it can naturally grow. If you are growing it at home using a mesh bag, ensure that the bag is not too small and offers enough space for the lichen to grow freely. It is also important to avoid any physical interference that can damage the lichen.
Propagation Methods of Melanelia Sorediosa
Melanelia sorediosa, commonly known as black-eyed greenshield lichen, is a slow-growing lichen that can propagate effectively through various methods, including:
Vegetative Propagation
This method involves the detachment of small fragments or pieces from the parent thallus for reattachment to another substrate. The fragments need to be small and intact to optimize their chances of survival. Vegetative propagation is often a natural occurrence in lichen communities, with fragments transferring for new growth sites as they fall off or get disturbed.
Thallus Transplantation
Another propagation method for Melanelia sorediosa involves the transplantation of a thallus or a section of it onto a new substrate. This method may require the thallus to be kept moist and with proper microclimatic conditions to ensure initial growth and establishment. Thallus transplantation is often used to introduce new lichen populations into previously uninhabited areas.
Spore Dispersal
Melanelia sorediosa also produces spores, which can lead to the propagation of new individuals if the environmental conditions are suitable. Spores need to land in an appropriate substrate and have adequate moisture and nutrients for germination to occur. Spore dispersal is often aided by wind, rain, or animal movement and can lead to the colonization and establishment of new lichen communities.
With these propagation methods, Melanelia sorediosa can quickly establish colonies in suitable environments, contributing to its ecological significance in its habitat. It also allows for its preservation and possible inclusion in restoration projects for degraded habitats.
Disease Management
Melanelia sorediosa or black leather lichen can be susceptible to several diseases, such as:
- Fungal infections: These infections can cause leaf spots, stem cankers, and root rots in the plant. The damage can impede the plant's growth and result in stunted development, yellowing, and fall of leaves. To manage fungal infections, remove infected plant parts, avoid excess watering, improve air circulation, and apply fungicide sprays.
- Bacterial diseases: Common bacterial diseases that affect Melanelia sorediosa include bacterial leaf spot, bacterial blight, and bacterial canker. They cause wilting, yellowing, and blackening of leaves and shoots, which eventually result in complete defoliation and plant death. Control bacterial diseases by removing infected plant debris, avoiding overhead watering, using pathogen-free seeds, and applying copper-based bactericides.
Pest Management
Melanelia sorediosa is not usually affected by serious pests, but it can occasionally fall victim to:
- Aphids: These tiny insects suck sap from the plant, causing yellowing, wilting, and stunted growth. They secrete a sticky residue called honeydew, which attracts ants and sooty mold. To control aphids, use insecticidal soaps, neem oil, or spray a strong jet of water to dislodge them.
- Spider mites: Spider mites are common in dry, hot conditions, and they can cause leaf yellowing, webbing, and defoliation. To manage spider mites, maintain adequate humidity levels, avoid fertilizing with high-nitrogen fertilizers, and apply miticide sprays.
Regular pruning, adequate watering, and proper sunlight exposure can help Melanelia sorediosa stay healthy and less prone to infections and pests.
