Overview of Cynoglossum zeylanicum
Cynoglossum zeylanicum (Vahl) Thunb. ex Lehm., commonly known as hounds-tongue or Sri Lankan hounds-tongue, is a perennial herb that belongs to the Boraginaceae family. The plant is native to Sri Lanka, India, and parts of Southeast Asia. In Sri Lanka, the plant is known as "Weli rukaththana".
Description of Cynoglossum zeylanicum
The plant grows up to 60 cm in height and has a strong woody taproot. The leaves of the plant are oblong, hairy, and up to 10 cm in length. The flowers are small, pink, and grow in clusters. The fruit consists of four small nutlets, each containing a seed.
Uses of Cynoglossum zeylanicum
Cynoglossum zeylanicum is used in traditional medicine across Asia to treat a range of ailments, including respiratory infections, fevers, and skin diseases. In Sri Lanka, a decoction of the plant's leaves and stem is used as a blood purifier and to treat skin disorders. The plant is also used as a natural dye, producing a red color.
The plant has been found to contain several bioactive compounds, including alkaloids, flavonoids, and saponins, which have been linked to its medicinal properties.
Appearance of Cynoglossum zeylanicum
Cynoglossum zeylanicum is a hairy, perennial herb with oblong leaves and small pink flowers. The plant has a strong woody taproot and grows up to 60 cm in height. The fruit consists of four small nutlets, each containing a seed.
Overall, Cynoglossum zeylanicum is a valuable and versatile plant that has been utilized for its medicinal and dyeing properties across Asia.
Growth Conditions for Cynoglossum zeylanicum
Cynoglossum zeylanicum is an herbaceous plant found in tropical regions. It grows up to 60 cm in height, with slender stems and blue flowers. The plant prefers a well-drained soil and can grow in a variety of conditions.
Light Requirements
Cynoglossum zeylanicum grows best in full sunlight but can tolerate partial shade. The plant needs at least 6 hours of direct sunlight per day to thrive. Insufficient sunlight can lead to leggy growth and reduced flowering.
Temperature Requirements
Cynoglossum zeylanicum prefers warmer temperatures and cannot tolerate frost. The ideal temperature range for growth is between 18-27°C. The plant can survive in higher temperatures but may require additional water to prevent wilting.
Soil Requirements
Cynoglossum zeylanicum grows best in well-drained, fertile soils with a pH range of 6.0-7.5. The plant can tolerate a variety of soil types, including sandy, loamy, and clay soils. However, it cannot grow in waterlogged soils and requires good drainage to prevent root rot.
Cultivation Methods
Cynoglossum zeylanicum is a hardy plant that prefers moist and shaded conditions. It can be cultivated both indoors and outdoors. When cultivating indoors, it is recommended to use a pot with well-draining soil. The plant prefers slightly acidic soil with a pH between 5.5 and 6.5. Outdoor cultivation is possible in areas with a warm and humid climate.
The seeds of Cynoglossum zeylanicum can be sown directly on the soil surface or started indoors about six weeks before the last expected frost. The seeds should be lightly covered with soil, and the soil should be kept moist until the seeds begin to germinate. Germination usually takes about one to two weeks.
Watering Needs
Cynoglossum zeylanicum prefers moist soil and should be watered regularly. It is important not to overwater the plant, as this can lead to root rot. It is recommended to water the plant when the soil feels dry to the touch. When watering, make sure to water the soil and not the leaves to prevent fungal diseases.
Fertilization
The plant does not require frequent fertilization. However, adding a balanced fertilizer during the growing season can be beneficial. It is recommended to use a slow-release fertilizer that is high in nitrogen to promote foliage growth. Fertilizer should be applied in small quantities to avoid over-fertilization which can damage the plant.
Pruning
Cynoglossum zeylanicum does not require frequent pruning. However, trimming back the plant can promote bushier growth. Pruning should be done early in the growing season, and it is recommended to remove only the top growth to encourage lateral branching. Deadheading spent flowers can also help to promote blooming.
When pruning, it is important to use clean and sharp tools to avoid damaging the plant. The plant's sap can cause skin irritation, so gloves should be worn when pruning.
Propagation of Cynoglossum zeylanicum (Vahl) Thunb. ex Lehm.
Cynoglossum zeylanicum (Vahl) Thunb. ex Lehm. is a herbaceous plant that belongs to the family Boraginaceae. It is commonly known as Indian hound's tongue, and it is native to the Indian subcontinent. The plant can be propagated both by seeds and vegetative methods such as stem cuttings.
Propagation by seeds
The seeds of Cynoglossum zeylanicum can be collected from the mature fruits during the autumn season. The collected seeds should be cleaned and dried in the sun for a few days. The seeds can be stored in a cool and dry place until the next season for propagation.
For seed propagation, fill the trays with a well-draining potting mixture, and sprinkle the seeds on top of the soil surface. It is essential to keep the soil moist, but not water-logged, until the seeds germinate. The seedlings should be watered regularly, and after 6-8 weeks, they can be transplanted to individual pots.
Propagation by stem cuttings
The vegetative propagation of Cynoglossum zeylanicum can be achieved by stem cuttings. The cuttings should be taken from healthy and disease-free plants during the active growing season. It is recommended to use the tip cuttings that are about 5-6 inches long.
Remove the lower leaves from the cutting and dip the base of the stem in a rooting hormone powder. Plant the cutting in a well-draining potting mixture, and water it thoroughly. It is best to keep the cutting in a humid environment by covering it with a plastic bag or placing it in a greenhouse. After a few weeks, roots will emerge, and the cutting can be transplanted to a bigger pot.
Disease and Pest Management for Cynoglossum zeylanicum
Cynoglossum zeylanicum, commonly known as hounds tongue, is a herbaceous plant that belongs to the family Boraginaceae. It is an erect or slightly spreading annual or biennial plant that can grow up to 60cm in height. While this plant is often used in traditional medicine, it is susceptible to several diseases and pests that can cause significant damage. Hence, proper disease and pest management practices are necessary to maintain healthy plants.
Common Diseases
1. Powdery mildew: Powdery mildew is a fungal disease that affects the leaves of hounds tongue. It appears as white or gray powdery patches on the leaves, which can cause the leaves to curl and dry out. To manage this disease, the affected leaves should be removed immediately, and a fungicide should be applied to prevent further spread and infection.
2. Leaf spot: Leaf spot is a fungal disease that causes circular or irregular brown spots on the leaves of hounds tongue. This disease can lead to premature leaf drop, which can weaken the plant. To manage this disease, affected leaves should be removed, and fungicides should be applied to prevent further infection.
3. Stem canker: Stem canker is a fungal disease that affects the stems of hounds tongue. It can cause the stem to darken and dry out, eventually leading to the death of the plant. The best way to manage this disease is to remove and destroy infected plants to prevent further spread.
Common Pests
1. Aphids: Aphids are small, soft-bodied insects that feed on the sap of the plant. They cause the leaves to curl and can transmit viruses that can further damage the plant. To manage this pest, a natural insecticide made of soap and water or horticultural oil can be used to control the infestation.
2. Spider mites: Spider mites are tiny, sap-sucking pests that cause yellowing and curling of leaves. They often build webs on the underside of the leaves. To manage this pest, the affected plant can be sprayed with water to wash off the mites, and a miticide can be applied if necessary.
3. Caterpillars: Caterpillars are the larvae of butterflies and moths that feed on the leaves of the plant. They can cause significant damage to the foliage, which can weaken the plant. Handpicking caterpillars from the plant is an effective way of managing them. Bacillus thuringiensis (Bt) can also be applied as a biological pesticide, which is safe for the environment and non-target organisms.
Overall, proper management of diseases and pests is critical in maintaining healthy hounds tongue plants. It is important to monitor plants regularly and take prompt action to prevent further spread and infection.
