Origin
Thelomma mammosum (Hepp) A. Massal. is a species of lichen that belongs to the family Thelommataceae. It is found in various parts of the world, including Europe, Asia, and North America.
Common Names
The plant is known by several common names, including the "Breast-shaped Thelomma," "Breast Lichen," and "Nipple-lichen." These names are due to the plant's resemblance to a breast or nipple.
Uses
Thelomma mammosum has no significant economic or medicinal uses. However, it plays an essential role in the ecosystem as it provides shelter for microbes, insects, and other small organisms.
General Appearance
The plant has a unique and intriguing appearance. It is typically small, ranging in size from 1-5mm. The thallus (body) is initially a greyish-white and becomes yellow or greenish-yellow with age. The upper surface of the thallus is smooth, and in the center, there is a distinctive elongated, rounded or "breast-shaped" projection. The underside of the thallus is covered with short, branched rhizines that help attach the plant to the substrate on which it grows.
Light Requirements
Thelomma mammosum thrives best in shaded environments, which is why it is frequently found growing under the canopies of trees. The plant can tolerate partial to full shade.
Temperature Requirements
The plant prefers cooler temperatures compared to most other species in the subalpine and alpine regions, where it is commonly found. It can survive as low as -15 degrees Celsius, but its optimal range falls between 5 to 15 degrees Celsius.
Soil Requirements
Thelomma mammosum grows in well-draining, humus-rich soil, which retains moisture without becoming waterlogged. The plant commonly grows on decaying wood, logs, and forest litter. It prefers relatively acidic soils with a pH between 4.0 and 5.5.
Cultivation Methods
Thelomma mammosum is a small and delicate plant that requires specific growing conditions to thrive. It grows best in shaded areas, such as rock crevices or under trees. The plant can be propagated through stem cuttings or division of the clumps.
Watering Needs
This plant prefers a consistent moisture level. It should be watered frequently but not excessively to avoid waterlogged soil and root rot. As such, it is recommended to keep the soil moderately moist throughout the year, especially during the growing season. However, allow the soil to dry partially between watering.
Fertilization
Thelomma mammosum requires very little fertilization and can thrive on the nutrients provided by its growing medium. As such, it is recommended to use a balanced houseplant fertilizer once every few months during the growing season. Over-fertilization can cause harm to the plant's roots, so it is essential to follow the recommended dosage instructions carefully.
Pruning
Thelomma mammosum is a slow-growing plant that seldom requires pruning. However, it may require trimming back when it outgrows its space or to maintain its shape. Trimming should be done during the growing season. The trimmed area can also be used to propagate the plant.
Propagation of Thelomma mammosum
Thelomma mammosum (Hepp) A. Massal. can be propagated through vegetative and asexual means.
Vegatative Propagation
Vegetative propagation can be achieved through stem cuttings. The stem cuttings should be taken from the parent plant, and should be around 10-15 cm long. The cuttings should be taken in spring or early summer when the plant is actively growing. The leaves on the lower half of the cutting should be removed, and the cutting should be planted in well-draining soil with a rooting hormone. The cutting should be watered regularly, and kept in a warm, bright location. The cutting should root within 6-8 weeks, and can then be transplanted into a larger pot or directly into the ground.
Asexual Propagation
Asexual propagation can be achieved through division. The plant can be divided into smaller sections when it becomes too large for its pot. The roots should be carefully separated, and each section should have a good amount of root attached. Each divided section should be planted in a pot that is slightly larger than the previous pot and filled with fresh, well-draining soil. The plants should be watered regularly and kept in a warm, bright location until new growth emerges.
Disease Management
Thelomma mammosum is generally a hardy plant, but it is still susceptible to several diseases. The most common diseases that can affect this plant are fungal infections such as anthracnose, powdery mildew, and rust. Regularly checking the plant for any signs of disease is important in controlling them.
The best way to manage fungal infections is to practice good sanitation. This includes removing and destroying any diseased plant parts and properly disposing of them. Avoid watering the plant's leaves, as this can cause fungal growth. Fungicides can also be used to control fungal infections. However, it is important to use them as directed and to choose a fungicide that is labeled for use on Thelomma mammosum.
Pest Management
Several pests can also cause damage to Thelomma mammosum. The most common pests that affect this plant are aphids, spider mites, and scale insects. These pests can feed on the plant's sap, causing yellowing of leaves and stunted growth. Without proper pest management, the plant can eventually die.
The first step in managing pests is to identify them correctly. Once identified, proper pest control measures such as natural predators like ladybugs, or insecticides can be used. Using insecticides, it is important to use them as directed, and avoid overusing them, as this can lead to resistance. Additionally, pest-prevention strategies like regularly inspecting the plant and keeping the area around the plant free of debris can also help keep pests at bay.
