Description of Buellia punctata (Hoffm.) A. Massal. var. polyspora (Willey in Tuck.) Fink
Buellia punctata (Hoffm.) A. Massal. var. polyspora (Willey in Tuck.) Fink is a species of lichen that belongs to the family Caliciaceae. It is commonly known as a "dot lichen" due to its small, punctiform apothecia, or fruiting bodies, which are characteristic of this species.
Origin and Distribution
Buellia punctata is widespread and abundant in the United States, Canada, Europe, and Asia. Its range extends from the Arctic tundra to temperate forests, and it can grow on rocks, bark, and soil.
Uses
Buellia punctata is mainly used as a bioindicator of air pollution, as it is sensitive to sulfur dioxide, nitrogen oxides, and heavy metals. It is also used in the pharmaceutical industry as a source of bioactive compounds, such as usnic acid, which possesses antibacterial, antifungal, and anti-inflammatory properties.
Appearance
Buellia punctata has a thallus, or body, that is crustose and grayish to blackish in color. Its apothecia are small and black, with a diameter of 0.2-0.5 mm. The spores are hyaline, ellipsoid, and measure 14-20 x 7-12 µm.
Overall, Buellia punctata is a unique and important lichen species that is valued for its environmental and medicinal benefits.Light Requirements
The Buellia punctata var. polyspora grows best in bright indirect light or partial shade. It needs about 3-4 hours of sunlight per day to thrive, but too much direct sunlight can damage the plant. It is recommended to place it near a window with a sheer curtain or in a shaded outdoor area with filtered sunlight.
Temperature Requirements
This plant prefers moderate temperatures ranging from 60-75°F (15.6-23.8°C). It can tolerate slightly lower temperatures, but exposure to temperatures below 50°F (10°C) for an extended period can damage the plant. It is important to keep it away from drafts or any sudden temperature changes as it can also cause harm.
Soil Requirements
The Buellia punctata var. polyspora prefer well-draining soil with a pH range of 5.5 to 7.0. It thrives in slightly acidic to neutral soil. The soil should have good water retention properties as it prefers consistently moist soil. A recommended soil mix is two parts peat moss to one part sand or perlite. Fertilization is not necessary, but a light application of balanced fertilizer during the growing season can improve the overall health of the plant.
Cultivation methods
Buellia punctata var. polyspora is a type of lichen that is commonly found in rocky and mountainous regions. It can also be cultivated in pots or trays using a suitable substrate. The substrate used for cultivation should be porous and have good drainage to prevent waterlogging.
The lichen can be propagated through the use of thallus fragments. The fragments should be taken from healthy specimens and allowed to grow on the substrate. They can be grown under controlled conditions such as temperature and humidity, preferably in a shade.
Watering needs
The watering needs of Buellia punctata var. polyspora are relatively low. The lichen prefers moist conditions, but excessive watering can lead to waterlogging and the growth of harmful fungi.
It is advisable to water the lichen when the substrate is almost dry. The watering should be done gently and evenly using a watering can or spray bottle.
Fertilization
Buellia punctata var. polyspora does not require fertilization in the traditional sense. However, certain nutrients can be added to the substrate to enhance growth.
One of the most effective ways to add nutrients is through the use of liquid seaweed extract. The extract contains mineral nutrients such as potassium, magnesium, and calcium, which are essential for the growth of Buellia punctata var. polyspora.
Pruning
Pruning is not necessary when it comes to the cultivation of Buellia punctata var. polyspora. However, it is recommended to remove any dead or diseased thalli.
Thallus removal can be done using a sterile pair of scissors or forceps. It is essential to be gentle to avoid damaging the healthy thalli. Thallus removal should be done before watering to prevent disease spread.
Propagation of Buellia punctata var. polyspora:
Buellia punctata var. polyspora is a lichenized fungus that reproduces through both sexual and asexual methods. The propagation of this species mainly involves the use of vegetative fragments, fragmentation, and spores.
Vegetative Propagation:
Buellia punctata var. polyspora can be propagated vegetatively using thallus fragments. The fragments can be carefully separated from the parent plant and placed on a suitable substrate for growth. The substrate must be moist, with a pH range of 5.0 to 7.5, and with low levels of nitrogen and phosphorous. The fragments should be placed in a shaded area until they attach themselves to the substrate and begin to grow.
Fragmentation:
Fragmentation is another method of propagating Buellia punctata var. polyspora. This method involves breaking the plant into smaller pieces, which can then establish themselves as separate plants. The fragments can be gently detached from mature thalli and placed on a suitable substrate. Fragmentation can also occur naturally when the parent plant is subjected to physical stress.
Spore Propagation:
Buellia punctata var. polyspora produces spores, which can be used to propagate the plant. The spores are small, dust-like particles that are dispersed in the air. They can be collected using a sterile technique and placed on a suitable substrate for growth. The substrate must be moist, and the spores must be exposed to diffuse light for optimal growth. The spores can take up to several weeks to germinate and establish as new plants.
Overall, Buellia punctata var. polyspora can be propagated using both vegetative and spore methods. Growers must ensure the maintenance of proper growing conditions and sterile techniques to prevent contamination and ensure maximum growth.
Disease Management
Buellia punctata is generally a hardy species and is not susceptible to many plant diseases. However, it can develop fungal infections such as leaf spot, powdery mildew, and rust, especially under humid conditions. Fungal diseases can be managed by practicing good cultural practices such as proper watering, pruning, and maintaining good airflow around the plant. Also, applying fungicides can help to control and manage fungal diseases.
Pest Management
Like most plants, Buellia punctata is susceptible to insect pests. The most common pests that can infest this plant are spider mites and aphids. Spider mites can cause severe damage to the plant by sucking its sap, which results in leaf yellowing, distortion, and eventually leaf drop. Aphids, on the other hand, feed on the plant's sap and can cause distortion and stunted growth. To manage these pests, it is recommended to keep the plant leaves clean, prune any infested parts of the plant, introduce beneficial insects such as ladybugs and lacewings, and use insecticidal soaps or oils when necessary.
