Eastern mosquito fern is a native annual aquatic plant in the Water-fern family (Salviniaceae). It is widespread in eastern North America and northern South America, growing in still or very slow-moving water, shallow ponds, ditches and sluggish streams. It grows in partial to full sun, in permanent standing water. To propagate this plant, move divisions of it to a new area. To keep it alive when temperatures dip, overwinter it indoors. Propagate by dividing the colony. Simply transfer a portion of the colony to a new suitable habitat. The delicate, lacey, scale-like leaves overlap and float on the water’s surface, forming a dense mat with the roots trailing below the surface. New leaves are a bright green or gray green and can fade to rusty red, especially if grown in bright conditions. The leaflets house a symbiotic blue-green alga ( Anabaena azollae ) that fixes nitrogen. This very short plant grows less than 1 inch tall but can break off and form a mat that covers the water’s surface very quickly, making it difficult for mosquitoes to deposit their eggs, hence the common name "mosquito fern." Another explanation is that this fern is associated with mosquitoes, as they both favor similar environments. Use it in water gardens, ponds or aquaria. The leaves are normally not eaten by fish. It is a rapidly growing and spreading aquatic plant, which may affect the location chosen for its use. Insects, Diseases, and Other Plant Problems: No serious problems.
Curated pairwise relationships between this plant and others in the library — who feeds
whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.
No curated interactions recorded for this species yet.
Also noted by NC State
Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell
apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.
Full sun (6 or more hours of direct sunlight a day) | Partial Shade (Direct sunlight only part of the day, 2-6 hours)
Soil drainage
Frequent Standing Water | Occasionally Wet
Available space
Less than 12 inches
NC region
Coastal; Piedmont
Growth rate
Rapid
Maintenance
Medium
Form & Appearance
Habit / form
Spreading
Texture
Fine
Leaf color
Gray/Silver; Green; Red/Burgundy
Leaf type
Fronds
Leaf margin
Lobed
Leaf size
< 1 inch long, < 1 inch wide
Hairs present
Yes
Leaf detail
Lacey, bright green to gray green fronds arranged in two rows of .5 mm long scale-like leaves with two lobes. The upper leaf is above the surface and the lower larger leaf floats below. On the upper lobe leaves have one celled hairs. Turn reddish in full sun and during fall.
Fall color
Red/Burgundy
Flower detail
No flowers.
Fruit detail
No fruits. Magaspores (female gameophytes) and microspores (male gametophyte) appear from June to September.
Stem detail
Prostrate stems branch
Wildlife & Ecology
Native status
Native
Origin
Americas
Wildlife value
This plant benefits waterfowl and shorebirds.
Play value
Wildlife Cover/Habitat
Food & Medicine
Harvest time
Summer
Uses (ethnobotany)
Grown in rice paddies as a green fertilizer or used as animal feed. It is being studied as a biofuel and has been used for pollution mitigation.