Callitriche stagnalis, commonly known as Starwort or Common Water-starwort, is an aquatic plant species that can be found in freshwater habitats such as ponds, lakes, and slow-moving streams.

Here is a detailed description and care guide for Callitriche stagnalis:

Description:

Callitriche stagnalis is a small, delicate plant with slender stems and opposite leaves. The stems can grow up to 20 cm (8 inches) in length and are typically submerged in water. The leaves are small, narrow, and have a distinct star-like shape, giving the plant its common name. The leaves may vary in color from bright green to reddish-green. It can form dense mats or floating clusters in the water.

Care Guide:

Lighting:
Callitriche stagnalis prefers moderate to high light levels. Provide a minimum of 2-3 watts per gallon of full-spectrum light for optimal growth. If grown outdoors, ensure it receives partial shade to avoid excessive sun exposure.

Water Parameters:
Maintain a water temperature between 18-26°C (64-79°F) for optimal growth. The pH level should be slightly acidic to neutral, ranging from 6.0-7.5. It can tolerate a wide range of water hardness, but prefers soft to moderately hard water.

Nutrient Requirements:
Starwort can adapt to a variety of nutrient conditions. It can absorb nutrients directly from the water column but can also benefit from supplemental fertilization. Adding a liquid fertilizer or root tabs rich in macro and micronutrients can promote healthier growth.

Substrate:
Although not mandatory, a nutrient-rich substrate can provide additional nourishment for the plant. A fine-grained substrate like sand or a specialized aquatic plant substrate is ideal for root establishment.

Propagation:
Callitriche stagnalis can reproduce through both vegetative and sexual propagation. Vegetative propagation occurs when the plant produces side shoots that can be separated and replanted. Sexual propagation occurs through the production of flowers and subsequent seed formation.

Maintenance:
Regular pruning is generally not required, but occasional trimming may be necessary to maintain the desired shape and prevent overgrowth.
Remove any dead or decaying plant matter to maintain water quality.
Ensure good water circulation to prevent stagnation and maintain oxygenation.

Compatibility:
Callitriche stagnalis is a versatile plant that can be used in various aquarium setups, including community tanks, shrimp tanks, and planted aquariums. It provides hiding places and grazing areas for small fish and invertebrates.

Overall, Callitriche stagnalis (Starwort) is a beautiful and adaptable aquatic plant that adds a natural touch to freshwater aquariums. With proper care and suitable water conditions, it can thrive and provide a visually appealing environment for aquatic inhabitants.