Origin
Pertusaria granulata (Ach.) Mull. Arg. is a type of lichen that is native to many regions around the world. It can be found in North and South America, Europe, Asia, and Africa.
Common Names
Common names for Pertusaria granulata include "grainy shield lichen," "rock rim lichen," and "gray shield lichen."
Uses
Pertusaria granulata does not have any known medicinal uses. However, it is used as a bioindicator of air quality in urban and rural areas. This lichen is sensitive to air pollutants such as sulfur dioxide and nitrogen oxides, and can absorb these chemicals from the air. Scientists can measure the amount of pollutants that are absorbed to determine the air quality of a given area.
General Appearance
Pertusaria granulata is a crustose lichen that grows on rocks, soil, and tree bark. It typically has a gray to brownish-gray color and a flaky or granular texture. The plant produces small, shield-like structures that are about 1-3 millimeters in diameter. These structures are usually flat with a slightly raised edge and a central depression. The underside of the shield is black or brown and has root-like structures called rhizines that help attach the plant to its substrate.
When viewed under a microscope, the vegetative body (thallus) of Pedusaria granulata appears to have a sea of tiny grains, hence the common name "grainy shield lichen".
The fruiting body (apothecia) of this lichen is small and circular, with a diameter of 0.5-1 millimeters. It is reddish-brown in color and has a finely granular texture. The apothecia produce spores that make it possible for the plant to reproduce and spread.
Overall, Pertusaria granulata has a distinctive appearance that makes it easy to identify in the field, even for non-experts.
Growth Conditions of Pertusaria granulata (Ach.) Mull. Arg.
Pertusaria granulata is a crustose lichen species that prefers to grow in dry habitats. It is commonly found in open, exposed areas such as rock surfaces and bare soil. The growth conditions for this species are as follows:
Light Requirements
Pertusaria granulata can tolerate moderate to high levels of sunlight exposure. However, it cannot survive in complete shade as it requires a certain amount of light for photosynthesis. It typically grows in open habitats with direct sunlight exposure.
Temperature Requirements
The ideal temperature range for the growth of Pertusaria granulata is between 10°C to 20°C. It can tolerate slightly higher temperatures but may dry out faster in hot and dry conditions. During extreme heat, the lichen can become dormant and resume its growth when conditions are favorable.
Soil Requirements
Pertusaria granulata is a lichen species that does not have roots, so the quality of the substrate it grows on is crucial. It prefers well-drained and nutrient-poor soils. It usually grows on rocks, gravels, and soils with low organic matter content. The lichen can resist desiccation for long periods and can grow in soils with low water content.
Cultivation Methods for Pertusaria Granulata
Pertusaria granulata can be propagated by sowing its seeds in a suitable substrate or by grafting. This plant prefers to grow in a warm, dry, and well-lit environment. It is important to maintain the correct humidity level to avoid the growth of fungi and bacteria that could damage the plant.
Watering Needs for Pertusaria Granulata
This plant species needs regular misting or spraying to maintain proper moisture levels. Use a gentle mist to avoid washing away the plant's nutrients. Keeping the plant moist is crucial to its survival, especially during hot and dry periods.
Fertilization of Pertusaria Granulata
Pertusaria granulata is a slow-growing plant, and it is not necessary to fertilize it frequently. However, if the plant is growing in a substrate without sufficient nutrients, it may require some additional feeding. Use a gentle, low-nitrogen, and water-soluble fertilizer diluted to half-strength every two to three months.
Pruning of Pertusaria Granulata
Pruning isn't a necessary task for this plant but can help to shape it as it grows. If you decide to prune it, make sure to do so in the spring to avoid causing damage to the plant. Cut the branches back to just above a healthy leaf node or bud. This will encourage new growth on the branch while also maintaining the overall shape of the plant.
Propagation of Pertusaria granulata
Pertusaria granulata (Ach.) Mull. Arg. is an epiphytic lichen that typically grows on the bark of trees. Propagation refers to the process of reproducing or multiplying plants or lichens. This species can be propagated using a variety of methods.
Fragmentation
Fragmentation is a method of propagation that involves breaking off a piece of the lichen, which then grows into a new thallus. For Pertusaria granulata, this can be accomplished by carefully breaking off a small section of the thallus and placing it on a new substrate. The new substrate should be similar to the original substrate and placed in a suitable growing environment.
Vegetative Propagation
Vegetative propagation is a method of propagation that involves using vegetative structures such as soredia or isidia to produce new thalli. Soredia are small, powdery structures that contain both fungal and algal cells and can be dispersed by wind or rain. Isidia are small, finger-like projections that grow from the thallus and can detach to form new thalli. To propagate Pertusaria granulata vegetatively, these structures can be harvested and placed on a new substrate in a suitable growing environment.
Sexual Reproduction
Sexual reproduction is a method of propagation that involves the fusion of gametes to produce new individuals. In Pertusaria granulata, the sexual spores are produced in the fruiting bodies (apothecia) and are dispersed by wind. To propagate the lichen sexually, the spores can be collected and placed on a suitable substrate.
Propagation of Pertusaria granulata can be challenging due to the specific requirements of the lichen. It is important to provide suitable substrates, growing environments, and propagation methods to ensure successful propagation.
Disease Management
Pertusaria granulata is generally resistant to diseases, and there are no known diseases that adversely affect the plant. However, if any fungal or bacterial diseases are noted on the plant, it is best to remove and destroy the infected parts to prevent the spread.
Pest Management
The most common pest that affects Pertusaria granulata is spider mites. Spider mites are tiny pests that suck sap from the leaves, and their damage can cause leaves to yellow and fall off. The use of predatory mites can help control spider mite populations in the plant. Aphids are another common pest that may affect Pertusaria granulata, and applying a solution of neem oil can help control their population. Mealybugs may also infest the plant, and spraying the affected parts with insecticidal soap solution can help control them.
