Aquatic plant forming large colonies; spreads rapidly. It has small, stemless, green, leaf-like fronds which float, singly or in small groups, on the water's surface. Each frond has a single, reddish, thread-like root dangling below it in the water.
Plants form olive to brown, rootless wintering buds, which sink to bottom. Root sheath not winged; roots often >1 inch, tips rounded; fronds (leaf-like parts) often reddish tinged, 3 to 5 veined, float, margins smooth, 1 to 1-1/2 times long as wide.
Habitat
Quiet, shallow water of lakes, ponds, river bottoms, swamps and marshes as well as slow-moving streams, stream pools (areas in a stream where the water is somewhat deeper) and beaver flowages (areas flooded by beaver dams).
Flower Characteristics
Often there is 1 tiny flower (rarely 2) per plant. They are held in 2 side pouches near the base of the plant with a narrow opening at the top. Flowers lack petals and sepals but have 2 stamens and a single style. However, flowers are seldom produced.
Leaf and Stem Characteristics
Fronds are 1/16 to 1/8 inch long, have a flat oval shape with rounded tips and are widest at or above the middle. They are 1 to 1-1/2 times longer than wide. Fronds have tiny raised bumps along the midvein above and are tinged with red or purple below.
Fruit and Seed Characteristics
The fruit is called a utricle. It is tiny, less than 1/16 inch long, thin-walled, may have 1 to several seeds and is bladder-like with a narrow opening at the top. When ripe, it does not split open to release the seed.
Seeds are smooth with 30 to 60 light veins. After fruit ripens, the seed stays within the fruit wall so that reproduction is mainly by special buds called turions which overwinter on the water bottom. In spring, they resurface, growing into a new plant.