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Watermeal

Watermeal (Wolffia columbiana), is a native species. Individual plants are barely visible to the human eye, but colonies can cover the water’s surface.

Watermeal

Description

Watermeal is a small, free-floating herb with a green circular frond less than 1/24 inch in diameter. Watermeal is the smallest and structurally simplest flowering plant. It consists of pinhead-sized fronds and lacks roots. A handful of these plants feels gritty, like wet corn meal -- hence the name “watermeal.” Two other similar species of watermeal occur in the Tennessee Valley region.

Habitat

Watermeal is native to much of the United States and grows in ponds, sloughs, lakes and sluggish streams. It often occurs with other free-floating species such as duckweed and waterfern. When found in pure colonies, watermeal gives a uniform, lime-green covering to still bodies of water. Watermeal is common in the Tennessee Valley, especially in farm ponds.

Identifying Features

What It Looks Like—Watermeal is a tiny, rootless floating plant. Its colonies form large, lime-green masses of “scum” on still water surfaces.

Where to Find It—Watermeal prefers quiet backwater areas but will travel almost anywhere depending on wind direction and current.

Similar Species—Watermeal is similar to duckweed but duckweed has roots, and watermeal is much smaller with no roots.

Drawbacks

Watermeal seldom produces any problems with water use on reservoir level.

Contact Us

We're always looking for more information about aquatic plants on TVA reservoirs. Let us know where and what you see, and send us your photos. Email us.