Alternanthera reineckii

Description

Alternanthera reineckii, commonly known as Scarlet Temple, is a beautiful stem plant native to South American riversides and wetlands. It’s highly prized in the aquarium hobby for its intense red, pink, and magenta leaves, which create a striking contrast against green foliage. While it can be grown in low-tech setups, its most vibrant colors are only revealed under high light and with CO2 injection, making it a moderately challenging but rewarding plant.

Care

To achieve the best coloration, Alternanthera reineckii requires high lighting and CO2 supplementation (20-30 mg/L). Use a nutrient-rich substrate or supplement regularly with iron and potassium via root tabs and liquid fertilizers. Maintain stable water parameters with a temperature of 22-28°C (71-82°F), a pH of 6.0-7.0, and soft to moderately hard water (up to 12 dGH). Avoid sudden changes in water conditions to prevent the plant from melting.

Propagation

Propagation is straightforward via cuttings. Simply trim a healthy stem of at least a few inches long, remove the lower leaves, and plant the cut end directly into the substrate. The cutting will develop a new root system and grow into a new plant.

Trimming

Frequent trimming helps maintain the desired height and encourages the plant to grow denser and bushier. Trim stems at any desired height and replant the healthy tops to easily propagate new plants and create a fuller look.

Notes, Tips, and Considerations

• Several popular cultivars exist, including ‘Mini’ (a smaller version for foregrounds), ‘Rosanervig’ (with light pink veins), and ‘Lilacina’ (a purple-hued variant).
• The plant is sensitive to drastic changes in water parameters, which can cause its leaves and stems to rot or ‘melt’.

Naturally Found

• Regions
  • South America
    • Countries: Bolivia, Brazil, Argentina, Paraguay, Uruguay
• Environment
  • Habitat: river, wetland
  • Water Type: freshwater
  • Water Depth: 0.1 – 1 m
  • Water Flow: still, slow, moderate
  • Light: high
  • Temperature: 22 – 28 °C
  • Humidity: high
  • Substrate: soil, mud