Overview
Hafellnera parasemella (Nyl.) Houmeau & Roux is a lichen species belonging to the family Pilocarpaceae. It is a small, foliose lichen that grows on rocks and soil in coastal habitats. The plant has several common names, including Hafellner's lichen, coastal umbilicaria, and greenbelt dust lichen.
Appearance
Hafellnera parasemella has a distinctive thallus that ranges in color from brownish-green to olive green. The thallus is foliose, with a diameter of 2-5cm and lobes that are 1-3mm wide. The margin of the thallus is raised and has irregular lobes, giving it a crinkled appearance. The upper surface is smooth and slightly shiny, while the lower surface is dark and has scattered rhizines. This lichen species is typically found growing on soil or under moisture-retaining mats.
Uses
While Hafellnera parasemella has no known medicinal uses, it has been used in the past as a food source by indigenous people. Some of the coastal tribes used it as a famine food. It was also used for pigment extraction, although this use is now considered obsolete. Hafellnera parasemella is commonly used as a bioindicator of coastal air pollution because it is particularly sensitive to atmospheric pollutants. As such, its presence is being monitored as an indicator of environmental health in coastal areas.
Origin
Hafellnera parasemella is native to coastal areas around the world, including Europe, North America, and Asia. It is particularly common along the rocky coasts of the Pacific Northwest, where it is found on rocks and soil in intertidal zones. This lichen species is also found in other coastal areas, including the Arctic. It is believed that its ability to thrive in these harsh environments is due to its tolerance of salt spray and its ability to photosynthesize at low temperatures.
Light Requirements
Hafellnera parasemella (Nyl.) Houmeau & Roux is a saxicolous lichen species that prefers to grow in well-lit habitats. In their natural habitat, they usually grow on sunny or partially shady surfaces such as tree trunks, rocky areas, walls, and soil. They require high light intensity for optimal photosynthesis, where they can absorb enough light energy to produce food for themselves.
Temperature Requirements
The temperature requirement for Hafellnera parasemella (Nyl.) Houmeau & Roux growth varies from one region to another, but it is generally found in cooler regions. It usually grows between an altitude of 200-3600 m above sea level, where the temperature usually ranges between 5-25 °C. The optimal temperature range for the growth of this lichen species is 10-20 °C, but it can tolerate temperatures as low as -10 °C.
Soil Requirements
The Hafellnera parasemella (Nyl.) Houmeau & Roux lichen species generally grows on a well-drained, well-aerated, and mineral-rich substrate. They are usually found growing on rocks, bark, and soil substrates that are rich in minerals such as calcium, magnesium, and potassium. This species can grow well in both acidic and slightly basic soils. However, the lichen becomes stressed under harsh conditions such as soil compaction or waterlogging, which can affect its growth and development.
Cultivation Methods
Hafellnera parasemella (Nyl.) Houmeau & Roux is an epiphytic lichen that requires specific growing conditions. As an epiphyte, it can be found growing on trees, rocks, and sometimes on the soil. To cultivate Hafellnera parasemella, you need to imitate its natural habitat by using a suitable substrate, adequate moisture, and proper light. To make an appropriate growing substrate, mix equal parts of peat moss and chopped tree fern or sphagnum moss. Spread this mixture over a flat surface and spray it with water until it becomes nearly saturated but not waterlogged. Then, place the lichen on top of the substrate and wrap it with a layer of nylon mesh to hold it in place.Watering Needs
Hafellnera parasemella requires consistently moist conditions to grow, but it is essential to avoid overwatering. You will need to water the lichen regularly to maintain the required moisture level. The best way to water it is by spraying it with a fine mist of fresh, clean water. For proper hydration, spray the lichen with water three times a week during the growing season - spring and summer. In the winter months, reduce watering to twice a week. Take care to avoid spraying too much water at once, which can lead to waterlogging and damage or destroy the lichen.Fertilization
Hafellnera parasemella is a lichen and does not require fertilizers to grow. It obtains its nutrients from the air and any organic material that accumulates on its surface. It would be best if you avoided using any fertilizers on it, as they can alter the substrate's pH and create an inhospitable environment for the lichen.Pruning
Hafellnera parasemella does not require any pruning. It grows slowly and will naturally take the form of its surroundings. If you want to remove any dead or damaged parts, you should do so carefully, taking care not to damage the healthy parts of the lichen. As a general rule, avoid touching the lichen as much as possible, as it is delicate and can be easily damaged.Propagation of Hafellnera parasemella (Nyl.) Houmeau & Roux
Hafellnera parasemella (Nyl.) Houmeau & Roux is a type of lichen that grows on rocks, especially on calcareous substrates. Propagation of this plant can occur via two primary methods, which are:
Vegetative Propagation
The vegetative propagation of Hafellnera parasemella is mainly through fragmentation, where the plant's fragments grow and give rise to new individuals. Upon fragmentation, a fragment that contains both the symbiotic algae and fungi can regenerate slowly into a new plant. However, the primary mode of vegetative propagation is through the dispersion of fungal cells through haploid spores. The fungal spores can colonize new surfaces, and where meeting with a compatible photobiont, the spore may germinate and become a new lichen plant.
Sexual Propagation
The sexual propagation of Hafellnera parasemella is also possible- through the dispersal of gonidia-containing structures that aid in the formation of new lichen thalli. The sporangia-structures that contain spores- are usually specialized (called perithecia) and are formed after a sexual fusion of haploid cells from the photobiont and mycobiont. Following this, the controlled development of perithecia forming ascocarps refers to production of spores. The spore releases typically take place by wind or rainwater- and importantly, the spore germinates and grows when contacting the detritus after reaching an appropriate surface.
Therefore, both vegetative and sexual (with a more pronounced importance in the former) propagations depend on a complex set of ecological requirements such as choosiness in the selection of their microhabitat, mainly related to the calcareous substrate and the presence of other lichens.
Disease Management
Common diseases that may affect Hafellnera parasemella include fungal infections, such as powdery mildew, leaf spots, and rust. These diseases can be prevented by maintaining good air circulation around the plant, avoiding overcrowding, and ensuring that the plant is not watered too often. If infections do occur, affected leaves should be removed promptly, and fungicides may be used as directed to control the spread of disease.
Pest Management
Aphids, mealybugs, spider mites, and whiteflies are common pests that may affect Hafellnera parasemella. Regular monitoring of the plant can help detect pests early. Infestations can be treated with insecticidal soaps, neem oil, or other insecticides labeled for use on the plant and according to the instructions. It is important to follow all directions when using insecticides to prevent damage to the plant or harm to beneficial insects.
