Also known as Least Duckweed · Spotless Water Flaxseed · Spotless Watermeal
Wolffia arrhiza, the rootless duckweed, is the world's smallest flowering plant, a tiny free-floating aquatic that reproduces rapidly in still or slow-moving freshwater.
At-a-glance light, water, soil, and growing conditions from plant data
Bright
75% intensity
Prefers bright, indirect sunlight. Can tolerate some direct sun but may overheat or experience excessive algae growth.
Always standing
100% intensity
Requires still, freshwater with high nutrient content. Avoid hard or chlorinated water.
None (aquatic)
50% intensity
Warm
75% intensity
Thrives in temperatures between 20-28°C. Avoid freezing temperatures.
Aquatic
50% intensity
Low
25% intensity
Nutrients are absorbed from the water. Fertilization is usually not needed unless in a sterile environment.
Safety information from plant toxicity data
| Attribute | Value |
|---|---|
| Toxic for humans | No 0/5 intensity |
| Toxic for pets | No 0/5 intensity |
None
Key traits and growing stats from plant data
Watering, pruning, propagation, and repotting details from plant data
Wolffia arrhiza thrives in stagnant, nutrient-rich freshwater. Maintain a consistent water level, ensuring the plants remain fully submerged. Avoid chlorinated tap water.
Natural pond water or aged aquarium water is ideal. Frequent water changes are generally not necessary if the ecosystem is stable.
Pruning is not applicable to Wolffia arrhiza. Its growth is naturally regulated by its environment and nutrient availability.
Overpopulation can be managed by physically removing excess plants, which is beneficial for maintaining water quality and preventing the surface from becoming completely choked.
Propagation is exceptionally rapid. New plantlets, called fronds, bud off from parent plants.
Under optimal conditions (warm temperatures, nutrient-rich water, ample light), Wolffia arrhiza can double its population in a matter of days, making manual propagation unnecessary.
Repotting is not applicable as Wolffia arrhiza is a free-floating aquatic plant and does not have true roots or require a substrate. It lives on the water surface.
If it becomes overcrowded, simply scoop out a portion of the population to thin it.
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Monthly activity intensity for bloom and fruit across both hemispheres.
Flowering & fruiting calendar
Flowering & fruiting calendar
Photos of Rootless Duckweed (Wolffia arrhiza)
Where Rootless Duckweed (Wolffia arrhiza) is found
Density
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Common names and botanical synonyms
Botanical classification
| Rank | Name |
|---|---|
| Kingdom | Plantae |
| Division | Tracheophyta |
| Class | Liliopsida |
| Order | Alismatales |
| Family | Araceae |
| Genus | Wolffia |
| Species | Wolffia arrhiza |
Similar in genus Wolffia
Answers based on plant encyclopedia data
