Wolffia, or Watermeal: World Smallest Plant - The Smallest Flowering Plant

Native to Asia, the Wolffia, is considered one of the smallest flowering plants in the world at 1mm in diameter per plant. You can easily mistaken it for cornmeal floating in the water at first sight, therefore it is also commonly called Watermeal. It belongs to a genus that is made up of some of the smallest plants on earth. The family contains four genera, based upon the presence or absence of roots and the shape of their plant body. There are 38 Wolffia species in total with nine of them being the smallest ever discovered. A single plant is no larger than a grain of sand and weighs only about 200 micrograms, and a dozen plants can easily fit onto the head of a pin. Wolffia plants are found in bodies of water, covering the surface and often making the water look “green” as an effect. Up close, the Watermeal are bean shaped, and often have a smaller bud growing out of one end. The bud will eventually come of as another mature Wolffia plant. The Wolffia belongs to the group of Duckweed, small water organisms that have two leaves floating above the water.

The abundance of Watermeal is large, covering many parts of the world. It only consists of thalli, an undifferentiated vegetative tissue. The plants have no roots and grow in depressions on the water’s surface. Individuals often float together in pairs or form floating mats with other similar plants that also make the water home, such as Lemna and Spirodela species. It flowers only in one area, the cavity in the side of a plant.They reproduce asexually, although they still do have a single stigma and stamen, which contains one ovary; the minute flowers have only one stamen and one pistil (stigma). The anther contains pollen, and the pouch a Watermeal holds contains a daughter plant, or offspring. Because Watermeal don’t have roots, they absorb the nutrient from the water through the surface of their skin. They are considered problems to ponds that are being used for human purposes.

Besides being the smallest flowering plant, the Wolffia augusta also has some positive uses. Many Wolffia plants are found in tropical areas such as Asia, America, and in rain forests around the globe. Watermeal is native to Asia, where it is part of many people’s diets. It is said to have just as much protein as soybean. Scientist are currently trying foods made by the Wolffia. Like soybeans, the Wolffia is 40% protein, so they are actually healthy, making it a very high-protein human food source. Muffins, doughnuts, and bakery products use Wolffia in them to make the food healthier. In Asia, Watermeal is harvested from the water and eaten as a vegetable.

Ponds contaminated with Watermeal often have less nutrition in them. They also tend to have less oxygen, which other animals need to live in. Though the seed is extremely tiny, it makes up more than half the entire plant.

Wolffia angusta
Wolffia arrhiza
Wolffia australiana
Wolffia borealis
Wolffia brasiliensis
Wolffia columbiana
Wolffia cylindracea
Wolffia elongata
Wolffia globosa
Wolffia microscopica
Wolffia neglecta