Overview
Graphina parilis (Krempelh.) Mull. Arg. is a species of lichen that belongs to the family of Graphidaceae. It is primarily found in tropical regions and has been dubbed by a few common names such as smooth script lichen or script lichen.
Appearance
Graphina parilis has a grey to greenish-grey thallus that measures about 3 to 5cm in diameter. This makes it one of the largest species of the Graphina genus. The surface of the thallus is smooth and sometimes gently wrinkled, having an appearance similar to scar tissue, and has been observed to have a prominent texture which is seen as thin, black raised lines that criss-cross the surface in a pattern of fine loops.
Uses
Graphina parilis is mainly used in the medical sector for its antimicrobial properties. Its extract has also been used for the treatment of a range of ailments such as colds, influenza, digestive issues, and headaches. Furthermore, it is used in various industries, such as perfumery and cosmetics, for its pleasant smell and is also used to dye textiles and for paper production.
Origin and Habitat
Graphina parilis has its origins in the tropics, including South America, Central America, Africa, and Southeast Asia. It grows commonly on tree trunks and branches as well as on rocks, almost exclusively in areas with a tropical or subtropical climate and high humidity levels. The lichen is more commonly observed in primary and secondary rainforests.
Light requirements
Graphina parilis is an epiphytic lichen species that prefers bright and indirect light. It typically grows on bark surfaces that are partially exposed to sunlight, such as tree trunks and branches that are filtered through the canopy. In its natural habitat, Graphina parilis can be often found growing close to light gaps, where there is enough light to support photosynthesis, but not enough to cause desiccation.
Temperature requirements
Graphina parilis is a tropical and subtropical species that thrives in warm and humid environments. The optimal temperature range for its growth is between 18°C to 28°C, with a preferred range of 20°C to 25°C. The species can tolerate brief exposure to high temperatures up to 35°C and can withstand occasional freezing temperatures below 0°C, but extended exposure to such conditions may cause damage or death of the thallus.
Soil requirements
Graphina parilis does not have specific soil requirements since it grows on the surface of tree bark rather than in soil. However, it depends on the substrate for anchorage and nutrient absorption. The species prefers loose and rough bark surfaces that provide a stable foothold and good air circulation. The bark surfaces of trees that have a textured or ridged appearance, such as oak or pine, are often suitable for colonization by the species. Graphina parilis can also grow on dead wood, rocks, and man-made substrates such as concrete or roofing tiles.
Cultivation of Graphina parilis
The plant Graphina parilis is a lichen and is primarily found in the wild. However, it is possible to cultivate this plant under controlled conditions.
To cultivate Graphina parilis, it is recommended to use a substrate consisting of rocks or bark. The substrate should be free of contaminants that could harm the plant. A controlled environment with moderate light and humidity levels will also facilitate its growth. The ideal temperature range for the cultivation of Graphina parilis is between 15-25°C.
Watering Needs of Graphina parilis
Graphina parilis is a drought-tolerant plant, and as such, does not require frequent watering. Water should be provided only when the substrate has become completely dry. Overwatering can lead to the death of the plant, as it is highly sensitive to excessive moisture.
Fertilization of Graphina parilis
Fertilization is not necessary for the cultivation of Graphina parilis. This plant obtains its nutrients from the air and the substrate it grows on. Therefore, the use of fertilizers can actually harm the plant and is not recommended.
Pruning of Graphina parilis
Graphina parilis does not require pruning as it is a slow-growing plant. However, it is important to remove any dead or diseased parts to avoid the spread of infection. When removing dead parts, it is essential to be gentle and avoid injuring the living parts of the plant.
Propagation of Graphina parilis
Graphina parilis (Krempelh.) Mull. Arg., commonly known as "rock shield lichen," is a slow-growing lichen that primarily grows on rocks, tree trunks, and branches. It is a fascinating lichen due to its unique physical features.
Vegetative Propagation
Vegetative propagation of Graphina parilis can be achieved through fragmentation. In this method, a small piece of lichen is detached from the main body and then attached to a suitable substrate of similar texture. The lichen will eventually establish itself on the new substrate and continue to grow. A significant advantage of this method is that the genetic makeup of the new lichen is identical to the parent lichen.
Asexual Propagation
Graphina parilis can also reproduce asexually through soredia. A soredium is a small, reproductive structure that grows on the lichen's thallus. It contains both algal cells and fungal hyphae that give rise to a new thallus when it breaks off and lands on a suitable substrate. Soredia of Graphina parilis are dispersed by wind or water. This method of reproduction allows for a large number of offspring, but each soredium has a different genetic makeup than the parent lichen.
Sexual Propagation
Graphina parilis also reproduces sexually, but this method is less common. Sexual reproduction occurs when the lichen produces a fruiting body called an apothecium. The apothecium contains asci (sac-like structures) that produce spores. When the spores are released, they can germinate into new lichens if they land on a suitable substrate.
In conclusion, Graphina parilis can be propagated vegetatively through fragmentation, asexually through soredia, or sexually through apothecia. Each method of propagation has its advantages and drawbacks, so choosing the appropriate method depends on the specific needs of the situation.
Disease Management
Graphina parilis is known to be susceptible to various kinds of fungal diseases. Some of the common fungal diseases that can affect Graphina parilis are:
- Anthracois disease: It is caused by the fungus Stegophora ulmea. This disease is characterized by the formation of dark spots on the leaves and stems. The leaves may eventually fall off, and the plant may become defoliated. To manage this disease, it is important to remove the affected leaves and stems immediately to prevent the spread of the fungus. Fungicides can also be used to control the disease.
- Powdery mildew: It is caused by the fungus Erysiphe cichoracearum. This disease is characterized by the formation of a white, powdery coating on the leaves, stems, and flowers. To manage this disease, it is important to maintain good air circulation around the plant and avoid overcrowding. Regularly spraying the plant with fungicides can also help control the disease.
- Phytophthora root rot: This disease is caused by the fungus Phytophthora nicotianae. It can lead to wilting, yellowing of leaves, and stunted growth of the plant. To manage this disease, it is important to provide proper drainage to prevent waterlogging and avoid overwatering of the plant. Fungicides can also be used to control the disease.
Pest Management
Graphina parilis is also affected by various pests that can cause damage to the plant. Some of the common pests that can affect Graphina parilis are:
- Aphids: These pests can cause damage to the plant by sucking the sap from the leaves and stems. To manage this pest, it is important to keep the plant clean and free of debris. Regularly spraying the plant with insecticides can also help control the pest.
- Mealybugs: Mealybugs can cause damage to the plant by feeding on the sap and secreting a sticky substance, which can attract ants and lead to the growth of mold. To manage this pest, it is important to keep the plant clean and free of debris. Regularly spraying the plant with insecticides can also help control the pest.
- Spider mites: These pests can cause damage to the plant by feeding on the sap and causing yellowing of the leaves. To manage this pest, it is important to keep the plant clean and free of debris. Regularly spraying the plant with insecticides can also help control the pest.
