Reproduction by Budding
Duckweed reproduces by two methods, budding and seeding. Budding means that the oldest fronds of the plant develop pouches on their stems, containing new buds. The buds eventually split through the pouches and resemble dark green fronds. These tiny plants are called turions and they are dormant during the winter months, sinking down to the bottom of the pond until the spring when they float back up to the top as adult plants. During the warm months they reproduce rapidly using the budding method without having to sink to the bottom. They merely bud and the new plant reaches maturity while still connected to the adult plant. The turions have no roots but the mature plants have a single root that dangles down into the water to gather nutrients.
Seeding, although uncommon, is possible with duckweed. When the fall season ends and winter begins, the seeds emerge from the old flower pods and sink to the bottom of the pond in order for germination to take place where the nutrients are the strongest. During the process of the winter, the seeds become turions and eventually adult plants that pop to the surface in the spring. Duckweed has an extremely fast reproduction rate, and can, under ideal circumstances, double itself every few days.
Fast Reproductive Cycle
Bright sunlight assists these plants in their reproductive cycle, but they are incredibly short-lived, each plant only surviving five to six weeks. However, during that period of time thousands of new plants can sprout and break off from the older plants. These plants easily cover small ponds with a green carpet, which can only be controlled through periodic removal of some of the plants or by keeping fish in the pond to eat them.