Staurothele umbrina (Wahlenb.) Tuck.
Staurothele umbrina, also known as Wahlenberg's lichen, is a species of lichen in the family Verrucariaceae. It was first described by Göran Wahlenberg, a Swedish botanist and physician, and later renamed by American lichenologist Edward Tuckerman in 1853. This lichen is found in various parts of the world including the United States, Canada, Europe, Asia, and Africa.
Common Names
Staurothele umbrina has several common names depending on the region. It is commonly called Wahlenberg's lichen after its discoverer, Göran Wahlenberg. Other common names include rock black lichen, Verrucaria umbrina, and epilichen umbrinus.
Uses
Staurothele umbrina does not have any documented uses in traditional medicine or cuisine. However, it plays an important ecological role in the habitats where it is found by providing a food source for animals such as reindeer and mountain hares. It also improves soil structure by retaining water and nutrients in habitats where other plants have difficulty growing.
General Appearance
Staurothele umbrina is a crustose lichen that forms thin, blackish-grey patches on rocks, gravels, and soil surfaces. It has a smooth to slightly wrinkled surface and is either circular or irregularly shaped. It ranges in size from less than 1 cm to 10 cm in diameter. The underside of this lichen is black and often has projections or small papillae. It has apothecia, tiny round to elongated structures that produce and release spores, which are black and raised above the thallus surface.
When viewed up close, Staurothele umbrina has a smudgy appearance due to the lack of distinct growth patterns. It can be distinguished from other similar lichens by its black underbelly and tendency to form thin patches rather than clumps.
Light Requirements
The plant Staurothele umbrina thrives in moderate to low levels of light. It should not be exposed to direct sunlight or high-intensity lighting, which can harm the delicate foliage. Therefore, it is ideal to place it near east or west-facing windows where it can receive dappled sunlight. If grown indoors, fluorescent lighting can support its growth.
Temperature Requirements
Staurothele umbrina is an adaptable species that can withstand a wide range of temperatures. Ideal temperatures for growth and development range from 18°C to 24°C. However, fluctuations within this temperature range may help promote better growth and flowering in some cases. During winters, it is recommended to ensure that the plant does not receive cold drafts from windows or doors.
Soil Requirements
Staurothele umbrina grows best in moist, organic-rich, and well-draining soil. The soil should have a slightly acidic to moderately alkaline pH, ranging from 6.0 to 7.5. The plant prefers soils that have excellent drainage capabilities to prevent waterlogging, which can lead to root rot. It can also grow well in a variety of soil types, including sandy, loamy, and clay soils, provided they meet the other requirements.
Cultivation Methods
Staurothele umbrina is a lichen species commonly found in tropical and subtropical regions. The ideal conditions for its growth are moderate to high levels of humidity, direct sunlight, and warm temperatures. To cultivate Staurothele umbrina indoors, you need to simulate these conditions by providing bright light, a well-humidified environment, and a temperature range of 20 to 30°C.
Watering Needs
The watering needs of Staurothele umbrina are not high, as they are adapted to withstand drought and periodical water shortages. In fact, overwatering can be detrimental to their growth and development. Water your Staurothele umbrina only when the soil is completely dry, and do not allow it to sit in standing water as it can cause root rot and other diseases.
Fertilization
Staurothele umbrina does not have high nutritional requirements, and therefore, fertilization is not necessary. If you wish to provide your lichen with some extra nutrients, use a balanced liquid fertilizer diluted at half strength once a month during the growing season. Avoid fertilizing during the dormant period.
Pruning
Pruning is not required for Staurothele umbrina as they do not have any leaves, stems or branches that need trimming. However, you may need to remove any debris or dead parts that may accumulate on the surface. This is to prevent the growth of fungi, bacteria, and other pathogens that can affect your lichen’s health negatively. Use a soft brush to gently sweep off any debris or wipe your lichen’s surface with a damp cloth or sponge.
Propagation of Staurothele Umbrina
Staurothele umbrina is a slow-growing lichen that can be propagated through vegetative or asexual reproduction. The following methods are used for propagation:
Fragmentation
Fragmentation is the easiest method of propagation for Staurothele umbrina. The lichen can be divided into smaller pieces with a sharp blade or scissors. These fragments can then be attached to a suitable substrate to allow for growth.
Soredia Propagation
Soredia are small, asexual reproductive structures found on the surface of the thallus. They can be easily dislodged from the thallus and scattered to new substrate surfaces. These soredia will then begin to grow and develop into new individuals.
Isidia Propagation
Isidia are small structures that grow on the surface of the thallus and contain both fungal and algal cells. These structures can be detached from the parent thallus and attached to a suitable substrate. Isidia propagation is a slow process and requires consistently moist conditions.
Propagation of Staurothele umbrina can be tricky because it requires specific environmental conditions. Therefore, it is best to leave propagation to experts or skilled growers to ensure successful results.
Disease Management
Staurothele umbrina plants are prone to fungal diseases, particularly when grown in humid and moist conditions. Some of the common fungal diseases that can affect these plants include leaf spot, powdery mildew, and anthracnose.
To manage these diseases, it is important to promote good air circulation around the plant. Avoid overhead watering, and instead, water at the base of the plant. Remove any infected leaves immediately and dispose of them carefully to prevent the disease from spreading.
Consider using fungicides as a preventative measure. Copper-based fungicides can be effective against fungal diseases in Staurothele umbrina.
Pest Management
Like most plants, Staurothele umbrina is susceptible to pests. Some of the common pests that can affect these plants include spider mites, mealybugs, and scale insects.
To manage pests, ensure that the plant is clean and well-maintained. Regularly inspect your plant for any signs of pest infestations, such as yellowing leaves or small insects. Remove any affected parts and dispose of them properly.
Pests can be controlled with insecticides. However, it is important to choose an insecticide that is appropriate for the pest and safe for the plant. Consider using insecticidal soap or neem oil, as these are effective against a range of pests and less toxic to the plant and the environment.
