Commelina Nigritana Benth. - Plant Description
Commelina nigritana Benth. is a species of flowering plant in the family Commelinaceae native to tropical regions of Africa, including Angola, Cameroon, Congo, Gabon, Ghana, Guinea, Ivory Coast, Nigeria, Sierra Leone, and Uganda.
Common Names
Commelina nigritana is commonly known as Ogiek, Nyakimera, Akumani, and Kukumera in different regions of Africa.
Appearance
The plant is a perennial herb that grows up to 60 cm tall and has an erect or semi-erect stem with nodes that bear hairy, oval-shaped leaves. The flowers are small, blue, and clustered at the end of long stalks. The plant can reproduce both vegetatively and sexually, producing small tubers along the stem that can grow into new plants.
Uses
Commelina nigritana is used in traditional medicine to treat various ailments such as stomach pains, fever, diarrhea, and inflammation. The plant has also been found to contain bioactive compounds with anti-inflammatory, anti-diabetic, and antioxidant properties, making it a potential source of medicine for these conditions. Additionally, the plant is used as a leafy vegetable in some regions, often boiled or steamed and served with sauces or stews.
Growth Conditions for Commelina nigritana Benth.
Light: Commelina nigritana Benth. is a sun-loving plant and requires bright light to grow properly. It can tolerate some shade, but full sun is ideal for its growth. A minimum of 6-8 hours of direct sunlight per day is essential.
Temperature: Commelina nigritana Benth. thrives in warm and humid conditions. The ideal temperature range for its growth is between 25-30 degrees Celsius. Cold temperatures below 10 degrees Celsius can hinder its growth, and frost can cause damage to the plant.
Soil: The plant prefers well-draining, nutrient-rich soil. It can tolerate various soil types, including loam, sand, or clay. However, clay soil should be amended with organic matter to improve drainage. The pH of the soil should be between 6.5 and 7.5, which is slightly acidic to neutral. It is sensitive to waterlogged soil, which can cause root rot and kill the plant.
Water: Commelina nigritana Benth. requires consistent and regular watering. It prefers moist soil, but it should not be waterlogged. Overwatering can cause damage to the root system and leaves. The plant should be watered when the top 1-2 inches of soil is dry. During the dry season, supplemental watering can be done to maintain adequate soil moisture.
Fertilizer: The plant can benefit from regular fertilization. It can be fertilized with a balanced fertilizer, with an equal ratio of nitrogen, phosphorus, and potassium. Fertilization can be done every 4-6 weeks during the growing season, from spring through summer.
Cultivation
Commelina nigritana Benth. prefers a warm tropical climate and thrives in moist, well-draining soil. The plant can be propagated through stem cuttings or seed. Seed germination typically occurs within a few weeks, and the plant will start to grow quickly.
The plant should be placed in an area that receives partial or filtered sunlight. If grown indoors, make sure it is placed near a window with indirect sunlight. Commelina nigritana Benth. can also be grown outdoors as a ground cover or in a container garden.
Watering Needs
Commelina nigritana Benth. requires regular watering to keep the soil moist. The frequency will depend on the climate and the soil type. Generally, the plant needs to be watered once or twice a week, ensuring that the soil is thoroughly soaked. It is essential not to over-water, as this can lead to root rot.
During the winter months, reduce the frequency of watering when the plant is in a dormant state.
Fertilization
The plant requires regular fertilization to promote growth and keep it healthy. Fertilizer should be applied every two weeks during the growing season, from spring to fall. Use a balanced fertilizer with equal amounts of nitrogen, phosphorous, and potassium.
The fertilizer should be diluted to half strength and poured around the base of the plant. Always follow the instructions provided on the fertilizer packaging.
Pruning
Pruning Commelina nigritana Benth. is not necessary, but it can help manage the plant's size and shape. Use clean, sharp scissors or pruning shears to remove any dead or damaged leaves. This will encourage new growth and improve the plant's appearance.
If the plant becomes too large, it can be cut back to its original size. It is best to do this during the growing season, spring to fall, to avoid any shock to the plant.
Propagation of Commelina nigritana Benth.
Commelina nigritana Benth. is a perennial plant that can be propagated both through seeds and vegetative means.
Propagation through Seeds
Propagation through seeds is the easiest and most common method for cultivating Commelina nigritana Benth. Seeds need to be sown in a nursery bed or seedling tray that is filled with well-draining porous soil. The best time for sowing the seeds is in the late winter or early springtime. The soil should be kept moist and the seeds should be left in a warm, lighted place for germination that usually occurs in 2-4 weeks. Once the seedlings reach a height of 2-3 inches, they can be transplanted to their final planting spot.
Propagation through Vegetative Means
Propagation through vegetative means involves dividing and planting of existing plants. This method is primarily used when one wants to quickly reproduce an existing plant with a desirable trait. The process involves splitting the rhizomes or tubers of the parent plant, and planting them in well-draining soil. The divided plants should be watered well in the beginning until they establish new roots in the soil. This method is usually best done during the late fall or early winter.
Disease Management
Commelina nigritana Benth. does not suffer from many diseases, but some do affect it. One major disease is root rot, which is caused by the fungus Pythium spp. This disease causes wilty, yellowed leaves, and the plant may eventually die. To manage this disease, avoid overwatering, ensure proper drainage, and use a fungicide application. Also, avoid planting in soils that hold water for long periods.
The fungi Fusarium spp. also cause wilt in Commelina nigritana Benth. plants. This disease is more apparent when the soil is overly wet or when the weather is too hot or too dry. Infected plants may wilt and eventually die if left untreated. To manage it, ensure that the soil is moist but not soaked, avoid overhead irrigation, and remove and destroy any infected plants.
Pest Management
Commelina nigritana Benth. usually does not suffer from major pest infestations, but some insects may cause trouble, especially when growing in greenhouses. Green peach aphids and spider mites are common pests that can infest the plant. Green peach aphids suck the plant juices, causing stunted growth and leaf curling. Spider mites appear as tiny moving dots on leaf undersides, and they also suck plant juices. As a result, there might be yellowed leaves and webbing formation on the plant leaves.
To manage these pests, insecticidal soap, neem oil, or a water jet can be used to wash off spider mites. Yellow sticky traps can also be used to attract and trap aphids. Companion planting with pest-repelling plants like marigold or planting the plant in a location far from other plants can also help to prevent infestation by these pests.
