Overview
Picrasma excelsa (Sw.) Planch., commonly known as bitterwood, quassia, or Jamaica quassia, is a plant species in the family Simaroubaceae. It is a tall, evergreen tree that is native to the Caribbean, Central America, and northern South America.
Appearance
The tree can grow up to a height of 40 meters and has a straight trunk that can reach a diameter of 60 centimeters. The bark is dark brown, rough, and fissured vertically. The leaves are compound, alternate, and drooping. They have a glossy, dark green color and are 20-30 cm long. The flowers are small and greenish-yellow, while the fruit is a capsule that contains small, winged seeds.
Common names
Bitterwood is the most common name for Picrasma excelsa, due to the intensely bitter flavor of the bark and wood. The name "quassia" is believed to have been derived from the name of a Surinamese healer, Quassi, who used the plant to treat fever and other illnesses. In Jamaica, the tree is known as Jamaica quassia or simply quassia, while in some parts of South America, it is called bitter ash or bitter bark.
Uses
Picrasma excelsa has been used for centuries in traditional medicine as a treatment for a wide range of ailments, including fever, gastrointestinal disorders, and parasitic infections. The bark and wood of the tree contain quassin, a bitter compound that has been found to have anti-inflammatory, antimicrobial, and antiviral properties.
In addition to its medicinal uses, bitterwood is also used in the production of alcoholic beverages, such as bitters and aperitifs, due to its extremely bitter taste. The wood is sometimes used for making furniture, flooring, and tool handles.
Typical Growth Conditions of Picrasma excelsa
Picrasma excelsa, commonly known as bitter wood, is a species of tree native to tropical regions of the Americas. It typically grows in humid and subtropical climates, with a preference for moist, well-drained soils. Here are some of the typical growth conditions required for the plant to thrive:
Light Requirements
Picrasma excelsa prefers bright, indirect light, but can tolerate some shade. In its natural habitat, it is often found growing in the understory of larger trees. Too much direct sunlight can scorch the leaves and cause damage to the plant. If grown indoors, it is recommended to place the plant near a window with filtered light.
Temperature Requirements
Bitter wood can tolerate a range of temperatures from 60°F (15°C) to 80°F (27°C). However, it is important to note that the plant prefers warm temperatures and high humidity. If grown in an area with lower temperatures, the growth rate may be slower, and the plant may go dormant in winter months. In colder climates, it is best to grow the plant indoors in a warm, humid environment.
Soil Requirements
Picrasma excelsa grows best in moist, well-drained soil that is rich in organic matter. The soil should have a pH range of 5.5 to 6.5. The plant is susceptible to root rot, so it is important to ensure that the soil is well-drained and not waterlogged. A mix of peat moss, perlite, and compost is recommended for optimal growth.
Overall, Picrasma excelsa is a low-maintenance plant that can be grown indoors or outdoors, as long as it is provided with the correct light, temperature, and soil conditions for it to thrive.
Cultivation
Picrasma excelsa, commonly known as bitter ash or Jamaican quassia, can be cultivated from seeds or by vegetative propagation. The plant prefers well-drained soil and full to partial sunlight. When propagating from seeds, it is essential to soak them in water for 24 hours before planting. The seeds should be sown about 0.5 cm deep in the soil and watered adequately until they germinate. Growing from cuttings is also possible by taking a healthy stem and planting it in well-drained soil suitable for the plant's growth.
Watering Needs
The watering needs of Picrasma excelsa vary depending on the season and environmental conditions. It is best to keep the soil consistently moist but not water-logged. In the growing season, water the plant generously and reduce the frequency during the dormancy period. Too little water can cause the leaves to wilt, and too much water can lead to root rot and other diseases.
Fertilization
Picrasma excelsa requires adequate nutrients to grow healthy. Fertilizers rich in nitrogen, potassium, and phosphorus should be applied during the growing season. It is recommended to use a slow-release fertilizer as it will provide nutrients over an extended period. Over-fertilization can harm the plant, so it is vital to follow the manufacturer's instructions.
Pruning
Pruning is necessary for maintaining the health of Picrasma excelsa. It is best to prune in late winter or early spring before new growth appears. The pruning process includes removing any diseased or damaged branches, removing any suckers that grow around the base of the plant, and shaping the plant. It is essential to sterilize pruning tools with rubbing alcohol before and after use to prevent the spread of diseases.
Propagation of Picrasma excelsa
Picrasma excelsa, commonly known as bitterwood or Jamaican quassia, is a small to medium-sized tree that is found in the Caribbean, South America, and Florida. The tree is valued for its medicinal properties and the wood is widely used in furniture making. Propagation of Picrasma excelsa is typically done through seeds or cuttings.
Seed Propagation
Seeds of Picrasma excelsa are the easiest way to propagate the plant. However, it is important to use fresh seeds because older seeds may not germinate. Seeding usually takes place in spring or autumn when the temperature is warm, and the moisture level is adequate.
Firstly, soak the seeds of Picrasma excelsa in water. This will help to remove any pulp or debris that may be attached to the seed. After soaking overnight, the seeds should be cleaned and then sown in a potting mixture. The seedlings will germinate within 2-3 weeks under optimal temperature and humidity conditions.
Cutting Propagation
Cutting propagation can also be used to propagate Picrasma excelsa. This method is suitable where seed propagation is not practical due to unavailability of seeds or other reasons. Taking cuttings in the early summer to early autumn period is ideal.
Take cuttings that are 8-10cm long with two nodes and remove the leaves at the bottom. The stem can be dipped in rooting hormone and inserted into moist sand, peat, and perlite mixture. Cover the pot with a plastic bag and keep it under shade with moderate watering. The cutting will develop roots within 3-4 weeks, and it can then be transplanted into a larger pot with well-draining soil.
Disease management
Picrasma excelsa, also known as bitterwood or Jamaican quassia, is generally a hardy tree with few serious disease problems. However, it may be susceptible to several fungal diseases, including leaf spot, anthracnose, and powdery mildew.
To manage these diseases, it is important to keep the area around the tree free of debris and fallen leaves that can harbor disease spores. Pruning the tree to allow for better air circulation can also help to reduce fungal growth. Fungicides can be applied if necessary, but it is important to follow label instructions carefully.
Pest management
Several pests may attack Picrasma excelsa, including scale insects, mealybugs, and spider mites. These insects can cause leaf yellowing and a general decline in the tree's health if left unchecked.
One method of pest management is to release beneficial insects, such as ladybugs and lacewings, to feed on the pests. Insecticidal soaps and oils can also be used to control insect populations, but care should be taken to avoid damaging the tree. It may be necessary to use a combination of these methods to effectively manage pest problems.
Regular inspections of the tree can help to identify pest infestations early on, allowing for prompt management and prevention of more serious issues.
