Origin
Hemizygia welwitschii (Rolfe) M.Ashby is a flowering plant that belongs to the family Lamiaceae. It is native to southern and eastern parts of Africa, including Ethiopia, Kenya, Tanzania, and Uganda.
Common Names
The plant is commonly known as the spiny hemizygia or the scratchy hemizygia.
Appearance
Hemizygia welwitschii is a perennial herb that grows up to 1m tall. The stem of the plant is green, woody, and branched, often covered in small spines or hairs. The leaves are narrow-elliptic to oblong-lanceolate, up to 8cm long and 3cm wide, with serrated edges and a prominent midrib. The leaves are hairless on the upper surface but sparsely hairy on the lower surface and petioles.
The plant produces flowers that are purple or white, arranged in dense terminal spikes up to 12cm long. The flowers are tubular and bilaterally symmetrical, with two lips, and about 1.5cm long.
Uses
Hemizygia welwitschii has been traditionally used in Africa for various medicinal purposes, including treatment of fever, stomachache, and diarrhea. The plant is also used in traditional African ceremonies and rituals to ward off evil spirits due to its thorny appearance.
Additionally, extracts from the plant have shown potential antimicrobial, anti-inflammatory, and antipyretic properties in research studies.
Light Requirements
Hemizygia welwitschii commonly known as Hemizygia, requires bright, but indirect light. The plant will thrive in a partial shade condition, with temperatures from 15 to 25°C. Placing the plant in direct sunlight for an extended period can damage its leaves. However, the plant should receive some morning and evening sun.
Temperature Requirements
Temperature requirements vary the most depending on whether the plant is indoor or outdoor. Hemizygia welwitschii typically prefers warm temperatures between 18 and 28ºC. During winter, it is essential to keep the plant away from cold drafts or frost. The plant does not like sudden temperature changes and therefore needs consistent temperature.
Soil Requirements
Hemizygia welwitschii does well in well-draining soil that is rich in organic matter. The soil's pH should be slightly acidic, with a pH between 6.0 and 6.5. The plant requires regular watering during the growing period and should never dry out. It is also important to avoid overwatering which can lead to root rot and other plant diseases.
Cultivation
Hemizygia welwitschii is native to Angola, Namibia, Zambia, and Zimbabwe and is commonly known as the scented hemizygia. This plant requires a warm climate with a temperature range of 18 to 26 degrees Celsius. It grows best in well-drained soil in a location with full sun exposure.
The plant should be propagated through stem cuttings taken during the growing season. Cutting approximately 10 cm long with at least two nodes is ideal. The cuttings should be placed in a mixture of soil and sand and kept moist until roots form.
Watering Needs
Regular and consistent watering is essential for Hemizygia welwitschii. It requires moderate watering, and soil should be kept consistently moist. Overwatering may cause roots to rot, while under-watering can damage the plant.
Watering should be done at the base, avoiding getting the leaves wet, especially during periods of high humidity. The water should be free from too many chemicals as the plant may be sensitive to such water.
Fertilization
Hemizygia welwitschii requires regular and light feedings. The plant should be fertilized every two to three weeks during the growing season, using a balanced fertilizer. An application of organic matter, such as well-rotted manure, is ideal during the early spring. Nitrogen-rich fertilizers promote the growth of lush foliage, while phosphate and potassium fertilizers help in the blooming phase of the plant.
Pruning
Pruning is essential in the maintenance of Hemizygia welwitschii. The plant requires regular pruning to encourage bushier growth and profuse blooming. Pruning should be done after flowering in the summer, using sharp, sterile pruning shears.
The dead and diseased stems should be removed, and any stems that rub against each other should be eliminated. Light trimming of the plant's top gives it a neat and fuller look. Regular pruning helps to promote the circulation of air within the plant, reducing the chances of diseases and pests.
Propagation of Hemizygia welwitschii
The plant Hemizygia welwitschii (Rolfe) M.Ashby can be propagated through a variety of methods, including seed propagation, stem cuttings, and division.
Seed Propagation
Propagation of Hemizygia welwitschii through seed is possible but can be challenging. Seed should be sown in a well-draining mix and kept moist in a warm and bright location. Germination can take several weeks to months and can have low success rates.
Stem Cuttings
Propagation through stem cuttings is a more reliable method for Hemizygia welwitschii. Cuttings should be taken from mature stems and placed in a well-draining mix. Keep the soil moist and provide bright, indirect light. After a few weeks, roots should form, and new growth will emerge.
Division
Propagation through division is another option for Hemizygia welwitschii. This method is best done in the spring when the plant is actively growing. Carefully remove the plant from its pot or ground, and divide it into smaller sections, ensuring that each section has roots and leaves. Replant each section in well-draining mix and keep moist until established.
Overall, Hemizygia welwitschii can be propagated through a variety of methods, but stem cuttings and division are the most reliable. With proper care, the plant should grow and thrive.
Disease and Pest Management for Hemizygia welwitschii
Hemizygia welwitschii, also known as the Velvet-leaved Hemizygia, is a tropical plant commonly found in Angola, Malawi, and Tanzania. To keep this plant healthy, it is essential to prevent and manage diseases and pests.
Common Diseases
The Velvet-leaved Hemizygia is susceptible to a variety of diseases, including fungal leaf spots, root rot, and powdery mildew. These diseases can cause discoloration, wilting, and ultimately, death of the plant.
To prevent the occurrence of fungal leaf spots and powdery mildew, avoid overhead watering and instead use a soaker hose or watering can to water at the base of the plant. Remove any infected leaves and dispose of them properly to prevent the spread of the disease.
If the plant is infected with root rot, remove the plant from its pot and examine the roots. If they are brown, mushy, and have a foul odor, they are likely affected by root rot. Cut off any affected roots and repot the plant in fresh, well-draining soil.
Common Pests
The Velvet-leaved Hemizygia is also vulnerable to pest attacks, including mealybugs, spider mites, and scale insects. These pests can cause stunted growth, leaf drop, and yellowing of the leaves.
To manage mealybugs and scale insects, dab them with a cotton swab soaked in rubbing alcohol. For spider mites, mist the plant with water and apply insecticidal soap. It is important to note that when using insecticides, always follow the instructions on the label and avoid over-application that can be harmful to the plant.
Overall, good hygiene practices and proper care and maintenance of the Hemizygia welwitschii can prevent the occurrence of disease and pest attacks.
