Origin and Common Names
Ludwigia repens J.R. Forst. var. rotundata (Griseb.) Gomes, commonly known as Roundleaf Ludwigia, is a plant species belonging to the family Onagraceae. It is native to Central and South America and can be found in Argentina, Brazil, Paraguay, and Uruguay.
Uses
Ludwigia repens J.R. Forst. var. rotundata has various uses, including as an aquarium plant, a medicinal plant, and an ornamental plant. In the aquarium hobby, the plant is prized for its vibrant red color and ability to remove nitrates from the water. Herbalists and traditional medicine practitioners use the plant to treat various ailments, such as stomachaches, fever, and skin problems. The plant is also popular among gardeners as an ornamental plant due to its attractive foliage and vibrant color.
General Appearance
Ludwigia repens J.R. Forst. var. rotundata is a herbaceous plant that can grow up to 50 cm tall. The plant has an upright growth habit and can form dense stands with numerous stems. The stems are thin and often have many side branches. The leaves are small, lance-shaped, and round at the base, giving the plant its common name. The leaves are green on the upper surface and reddish-brown on the lower surface. The flowers of the plant are inconspicuous and have four petals that are yellow or orange in color.
Light Conditions
Ludwigia repens J.R. Forst. var. rotundata (Griseb.) Gomes thrives in moderate to high light conditions. It requires at least six hours of direct sunlight exposure daily to grow optimally. The plant will exhibit faster growth rates with more direct sunlight. However, too much sunlight may result in drying and wilting of the leaves. Therefore, it is recommended to provide partial shade during the hottest hours of the day.
Temperature Requirements
The plant grows best in temperatures ranging between 20-28°C (68-82°F). Ludwigia repens J.R. Forst. var. rotundata (Griseb.) Gomes is sensitive to cold temperatures and may not survive in low temperatures below 15°C (59°F). During winter, it is essential to provide additional heat sources or move the plant indoors to avoid damage.
Soil Requirements
The soil should have a neutral pH range of 6.5-7.5 for Ludwigia repens J.R. Forst. var. rotundata (Griseb.) Gomes to grow optimally. The plant prefers nutrient-rich substrate with moderate to high organic content. The substrate should be well-draining, as poorly drained soils may cause root rot. It is recommended to add fertilizers rich in potassium and iron to enhance growth. The plant can also grow well in an aquatic environment, and its roots can thrive in the substrate or water.
Cultivation Methods
Ludwigia repens J.R. Forst. var. rotundata (Griseb.) Gomes can be grown both submerged and emersed. As an emersed plant, it grows well in a well-lit aquarium with a nutrient-rich substrate. On the other hand, when grown submerged, this plant requires a nutrient-rich substrate and moderate to high lighting. The ideal temperature range for the growth of this plant is between 20 and 28 degrees Celsius.
Watering Needs
The Ludwigia repens J.R. Forst. var. rotundata (Griseb.) Gomes requires a constant supply of clean water to thrive. When grown submerged, the water should be changed once a week to prevent the buildup of harmful chemicals such as nitrates and phosphates. The plant should also be provided with a source of CO2, which is essential for its growth.
Fertilization
Fertilization is crucial for the growth and development of Ludwigia repens J.R. Forst. var. rotundata (Griseb.) Gomes. When grown in an aquarium, the plant should be provided with a nutrient-rich substrate. Additionally, liquid fertilizers can be added to the water to provide all the necessary nutrients. The fertilizers should be added as per the manufacturer's instructions and should not exceed the recommended dosage to avoid overfertilization.
Pruning
Pruning is necessary to control the growth of Ludwigia repens J.R. Forst. var. rotundata (Griseb.) Gomes. The plant has a tendency to grow quickly, and if left unchecked, it could overshadow other plants in the aquarium. Pruning should be done gently to avoid damaging the plant. This can be achieved by removing the top of the plant with a pair of scissors. The plant will then develop new shoots, which should be pruned regularly to control the growth of the plant.
Propagation of Ludwigia repens J.R. Forst. var. rotundata (Griseb.) Gomes
Ludwigia repens J.R. Forst. var. rotundata (Griseb.) Gomes is a highly popular and fast-growing aquatic plant. Propagation of this plant can be done through different methods,:
Stem cutting propagation
One of the most common methods of propagating Ludwigia repens J.R. Forst. var. rotundata (Griseb.) Gomes is through stem cuttings. For stem cutting, take a healthy stem of approximately 10-15 cm in length and make a cut at a 45-degree angle at the base of the stem. Remove the leaves from the bottom inch of the stem and then place it into the substrate. In a few weeks, new roots will start forming from the base of the stem. After around 4-6 weeks, when the new plant is well established, cut off the original stem.
Adventitious plantlets propagation
Ludwigia repens J.R. Forst. var. rotundata (Griseb.) Gomes produces adventitious plantlets along the length of its stem. These plantlets can be easily propagated by carefully detaching them from the stem and planting them in the substrate. It is necessary to ensure that the plantlets remain in contact with the substrate, either by burying them or by securing them to a stone or wood with an aquarium-safe adhesive.
Seed propagation
Seed propagation of Ludwigia repens J.R. Forst. var. rotundata (Griseb.) Gomes is also possible but it is relatively difficult in an aquarium environment. The seeds need to be planted in moist soil, which should then be kept moist until the seeds germinate. Once the seeds have sprouted, they can be transferred to the water-filled aquarium. However, this method requires specific conditions and is less reliable than the other methods of propagation.
Disease Management
Even though Ludwigia repens is a very resistant plant, it is still vulnerable to several diseases.
Leaf Blight: This fungal disease can quickly spread and kill entire plants. Infected leaves will develop brown spots which will eventually turn into holes. The best way to manage this disease is by removing all infected foliage and treating the plant with a fungicide.
Root rot: Overwatering can lead to root rot, which can be identified by yellowing leaves and a foul odor. To manage root rot, reduce watering and treat the plant with fungicide. Remove all the affected leaves and sterilize the soil with hot water.
Stem Rot: This disease usually appears due to overcrowding and excess moisture. Infected plants will look wilted and their stems will turn brown. To manage this, remove all infected plants and space them out more. Treat the soil with fungicide.
Pest Management
Ludwigia repens is also susceptible to several pests.
Aphids: These small insects feed on the sap of the plant, causing it to wilt and yellow. They can be managed by releasing beneficial insects such as ladybugs in the growing area, or by spraying the plant with insecticidal soap.
Spider mites: These pests are incredibly difficult to spot but can cause significant damage to the plant by puncturing the leaves and feeding on sap. The best way to combat spider mites is by regularly spraying the plant with water and a miticide. Remove any heavily damaged foliage.
Snails and Slugs: These pests will eat large holes in the leaves of the plant. To manage, use copper barriers around the plants or use snail bait.
