Origin
Caloplaca obliterans (Nyl.) Blomb. & Forss. belongs to the family Teloschistaceae, and is commonly found in North America, Europe, and Asia. It is a lichenized species, made up of fungal filaments and photosynthetic cells, and grows in rocky habitats such as cliffs, boulders, and gravelly soil.
Common Names
Caloplaca obliterans is commonly known as rock shield lichen due to its habit of forming a crust-like shield on rocks. Other common names include powdered moon lichen, and frosted lichen.
Uses
Caloplaca obliterans has no known traditional or modern uses in medicine, food, or industry. However, it is useful as an environmental bio-indicator, as it is sensitive to changes in air quality and pollution. Its presence or absence can indicate the level of air pollution in an area.
General Appearance
Caloplaca obliterans is a yellow-orange to bright orange crustose lichen, with a powdery, granular or pruinose surface. It grows in a circular or irregularly shaped pattern, and is closely attached to the substrate. Its thallus (body) is made up of small convex or flat scales, which are typically less than 1 mm in diameter.
The apothecia (fruiting bodies) of Caloplaca obliterans are rounded to slightly irregular in shape, and are usually less than 1.5mm in diameter. They are orange-yellow to reddish-brown in color, with a darker coloured outer rim. The spores are colorless and are typically less than 10 µm in size.
Light Requirements
Caloplaca obliterans typically grows in areas with moderate to high levels of sunlight exposure. In particular, it favors habitats that receive direct sunlight or partial shade. However, prolonged and intense exposure to sunlight may cause damage to the plant and inhibit its growth.
Temperature Requirements
The optimal temperature range for the growth of Caloplaca obliterans is between 10°C and 20°C. It can tolerate temperatures as low as -20°C and as high as 30°C but only for a short duration. In general, the plant prefers cool temperatures and is common in cool temperate regions.
Soil Requirements
Caloplaca obliterans is a lichen that grows on rocks, including granite, limestone, and sandstone. It does not require soil to grow and can thrive in areas with minimal amounts of soil. However, the plant does require a firm substrate, as it attaches itself firmly to the rock surface through a symbiotic relationship with fungi.
Cultivation of Caloplaca obliterans
Caloplaca obliterans is a species of lichen that grows on rocks and boulders in sunny, exposed locations. It requires well-drained soil and does not tolerate standing water or soil with high moisture content. The lichen can be grown in pots or directly attached to rocks in a rock garden or other suitable location.
Watering Needs of Caloplaca obliterans
Caloplaca obliterans requires very little watering. In fact, overwatering can be detrimental to the health of the lichen. It is important to allow the lichen to dry out between waterings. If grown in pots, water should be applied sparingly, and the amount of water should be reduced during periods of high humidity or rainfall.
Fertilization of Caloplaca obliterans
Caloplaca obliterans does not require fertilization. The lichen obtains its nutrients from the surrounding environment through photosynthesis. However, if grown in a pot or other artificial environment, a small amount of fertilizer designed for use on epiphytes can be applied once or twice a year to promote healthy growth.
Pruning of Caloplaca obliterans
Pruning is not necessary for Caloplaca obliterans. The lichen will grow and spread naturally. However, if the lichen is becoming too large for its location or interfering with nearby plants or structures, it can be gently removed or trimmed back. It is important to avoid damaging the lichen or its delicate thallus layer when pruning.
Propagation methods of Caloplaca obliterans
Caloplaca obliterans can be propagated through vegetative and sexual methods.
Vegetative Propagation
Vegetative propagation involves the use of vegetative parts of the plant, such as thallus fragments, to produce new individuals. Caloplaca obliterans can propagate vegetatively through fragmentation of the thallus. The fragmentation can occur naturally due to external factors such as wind or water. It can also be induced artificially through cutting and planting the thallus fragments on suitable substrates.
Sexual Propagation
Sexual propagation involves the use of spores to produce new individuals. Caloplaca obliterans has a complex reproductive biology that involves the formation of ascomata, which are structures that produce sexually reproductive spores known as ascospores. The ascospores are dispersed by wind and can colonize suitable substrates where they can develop into new individuals.
In conclusion, Caloplaca obliterans can be propagated through both vegetative and sexual propagation methods. The vegetative method involves the use of thallus fragments, while the sexual method involves the use of spores.
Disease Management for Caloplaca obliterans
Caloplaca obliterans is a hardy lichen species that is relatively resistant to many common plant diseases. However, it may still be susceptible to certain diseases, particularly if growing conditions are sub-optimal. One of the most common diseases affecting Caloplaca obliterans is a type of leaf spot caused by various fungal pathogens.
To manage fungal leaf spots, it's important to maintain good sanitation practices including removing any infected plant material and debris. Additionally, avoid overhead watering and irrigate at the base of the plant to avoid creating conditions that favor fungal growth. Applying fungicides may also help to control the spread of the disease.
Pest Management for Caloplaca obliterans
Caloplaca obliterans is relatively pest resistant and there are few pests that pose a significant threat to this lichen species. However, certain insects such as aphids, spider mites, and scale insects may occasionally feed on Caloplaca obliterans. These pests are often well controlled through natural predators and parasites, meaning that chemical control is not usually required.
If an infestation does occur, physically removing the pests by hand or applying insecticidal soap may help to control the problem. It's important to take a measured approach to pest control as using too many chemicals can harm beneficial insects and impact the overall health of the ecosystem.
