Overview
Spirodela polyrrhiza (L.) Schleid. var. masonii Daubs, commonly known as Mason's duckweed, is an aquatic plant that belongs to the duckweed family (Lemnaceae). The plant is found in freshwater ecosystems across North America, particularly in the eastern and central regions of the continent.
Appearance
Mason's duckweed is a small, floating plant that forms loose mats on the surface of slow-moving or still waters. The plant has round or oval-shaped leaves or fronds that are only 1-5 mm long, with up to three roots tapering from the lower surface of the fronds. The roots are only 1-2 cm long and contain no root hairs. The plant tends to form dense colonies that can cover large areas of water surface.
Uses
While Mason's duckweed is not commonly used as a food source, it is known to be an important food for aquatic animals, particularly waterfowl and some fish species. The plant is also valuable for the role it plays in water quality management. As a floating plant, Mason's duckweed helps to reduce the amount of nutrients in a body of water by absorbing excessive levels of nitrogen and phosphorus from the water. This process is known as phytoremediation, and it can help to improve water quality by removing harmful pollutants from the water.
Common Names
Mason's duckweed is known by a few common names, including common duckweed, greater duckweed, and duckmeat.
Light Requirements:
Spirodela polyrrhiza (L.) Schleid. var. masonii Daubs requires a moderately low light environment. It can grow well in partially shaded and shady conditions, but direct sunlight can cause harm to the plant. It is best to grow the plant under artificial light or in natural light with filtered sunlight.
Temperature Requirements:
The optimal temperature range for Spirodela polyrrhiza (L.) Schleid. var. masonii Daubs growth is between 20°C to 30°C. The minimum temperature required for this plant to grow is 10°C, while the maximum temperature is 35°C. The plant grows well in a climate that is not too cold or too hot.
Soil Requirements:
The plant requires a nutrient-rich, loamy soil that has good water-holding capacity. The soil should be neutral to slightly acidic, with a pH range of 6.0 to 7.5. It is important to ensure that the soil is well-drained and not waterlogged, as stagnant water can lead to root rot. The plant also requires regular fertilization to maintain optimum growth conditions.
Cultivation
Spirodela polyrrhiza (L.) Schleid. var. masonii Daubs is best grown in a container or pond. If grown in a container, select one that is at least 6 inches deep and 12 inches wide. Fill the container with a mixture of equal parts of loam, peat moss, and sand.
When grown in a pond, make sure the water is at least 6 inches deep and is not stagnant. This plant grows well in still or slow-moving water.
Watering Needs
Watering needs depend on the environment in which Spirodela polyrrhiza (L.) Schleid. var. masonii Daubs is grown. If grown in a container, water when the top inch of soil is dry. In a pond, the plant should receive enough water to keep the soil moist. Ensure that the water is not stagnant, and it never dries out completely.
Fertilization
Apply a balanced fertilizer to Spirodela polyrrhiza (L.) Schleid. var. masonii Daubs regularly. If grown in a container, add fertilizer to the water and mix well. In a pond, sprinkle the fertilizer around the plants. Do not over-fertilize as it may cause harm to the plant.
Pruning
Spirodela polyrrhiza (L.) Schleid. var. masonii Daubs does not require pruning. However, regularly check the plant for any dead or damaged leaves and remove them promptly, so they do not decay and affect the water quality. Make sure not to damage the plant while removing the dead/damaged materials.
Propagation of Spirodela polyrrhiza (L.) Schleid. var. masonii Daubs
Propagation of Spirodela polyrrhiza var. masonii Daubs is best done through division and fragmentation.
Division
Division is the most common method of propagating Spirodela polyrrhiza var. masonii Daubs. This can be done by physically dividing clumps of mature plants that have grown together. The divided plants can then be replanted in suitable containers or ponds, ensuring they are properly anchored to prevent them from floating away. It is best to carry out division in late spring or early summer when the plants are actively growing.
Fragmentation
Fragmentation can be used to propagate Spirodela polyrrhiza var. masonii Daubs in situations where the plants have become overcrowded and need to be thinned out. This involves gently separating the plants and floating the fragments in suitable growth conditions to develop new plants. It is best to carry out fragmentation in late spring or early summer when the plants are actively growing.
Propagation of Spirodela polyrrhiza var. masonii Daubs from seeds is not commonly done due to the plant's delicate nature. If propagation from seeds is required, it is best to collect the seeds in late summer or early autumn and plant them in suitable growing conditions immediately.
Disease Management
There are a few common diseases that may affect Spirodela polyrrhiza var. masonii. Gray mold (Botrytis cinerea) is a fungal disease that causes wilting and brown spots on leaves. To manage this disease, remove and destroy any infected parts of the plant and improve air circulation to prevent moisture buildup. Powdery mildew (Oidium sp.) is another fungal disease that results in a white, powdery coating on the leaves. To manage this disease, apply fungicides and reduce humidity levels around the plant.
Rhizopus stolonifer (black bread mold) is another fungal pathogen that can infect Spirodela polyrrhiza var. masonii, causing tissue death and rot. To manage this disease, avoid over-watering and ensure proper drainage. Remove and dispose of any infected plant material. Phytophthora infestans (late potato blight) may also cause brown spots and tissue death. To manage this disease, remove and dispose of infected parts of the plant and avoid getting water on the leaves when watering.
Pest Management
Spirodela polyrrhiza var. masonii is vulnerable to a few common pests, including spider mites, aphids, and thrips. Spider mites can suck sap from leaves, causing them to turn yellow and dry out. To manage spider mites, spray the plant with a hose and apply neem oil or insecticidal soap. Aphids can also suck sap from the plant and cause yellowing and distortion of leaves. To manage aphids, remove them manually or use insecticidal soap.
Thrips can cause black spots on leaves and flower petals as well as distorted growth. To manage thrips, spray the plant with neem oil or insecticidal soap. Mealybugs can also infest Spirodela polyrrhiza var. masonii, secreting a sticky substance as they feed. To manage mealybugs, remove them manually and/or apply insecticidal soap.
