Mosquito Fern Azolla caroliniana
Other Common Name(s):
- Phonetic Spelling
- a-ZOL-luh kair-oh-lin-ee-AN-uh
- Description
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Eastern mosquito fern is a native annual aquatic fern in the Salviniaceae family. This very short plant grows less than 1 inch tall but can break off and form a mat that covers available surface water very quickly making it difficult for mosquitos to deposit their eggs, hence the common name "mosquito fern".
Growing in still or very slow moving water it naturalizes in shallow ponds, ditches, and sluggish streams. The delicate lacey scale like leaves overlap and float above the surface forming a dense mat with the roots trailing in the water. New leaves are a bright or gray green and can fade to rusty red especially if grown in really bright conditions. To propagate this plant move sections of it to a new area. To keep it alive when temperatures dip, overwinter indoors.
The leaflets house a symbiotic blue-green alga (Anabaena azollae) that fixes nitrogen. Use it in water gardens, ponds, or aquariums though the leaves are normally not eaten by fish.
Insects, Diseases, and Other Plant Problems: No serious problems.
- See this plant in the following landscape:
- Cultivars / Varieties:
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- Tags:
- Cultivars / Varieties:
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Attributes:
- Genus:
- Azolla
- Species:
- caroliniana
- Family:
- Salviniaceae
- 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.
- Life Cycle:
- Annual
- Recommended Propagation Strategy:
- Division
- Stem Cutting
- Country Or Region Of Origin:
- Americas
- Wildlife Value:
- This plant benefits waterfowl and shorebirds.
- Play Value:
- Wildlife Cover/Habitat
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Whole Plant Traits:
- Plant Type:
- Annual
- Fern
- Native Plant
- Water Plant
- Habit/Form:
- Spreading
- Growth Rate:
- Rapid
- Maintenance:
- Medium
- Texture:
- Fine
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Cultural Conditions:
- Light:
- 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 To Plant:
- Less than 12 inches
- NC Region:
- Coastal
- Piedmont
- USDA Plant Hardiness Zone:
- 7a, 7b, 8a, 8b, 9a, 9b, 10a, 10b, 11a, 11b
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Fruit:
- Display/Harvest Time:
- Summer
- Fruit Description:
- No fruits. Magaspores (female gameophytes) and microspores (male gametophyte) appear from June to September.
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Flowers:
- Flower Description:
- No flowers.
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Leaves:
- Leaf Color:
- Gray/Silver
- Green
- Red/Burgundy
- Deciduous Leaf Fall Color:
- Red/Burgundy
- Leaf Type:
- Fronds
- Leaf Margin:
- Lobed
- Hairs Present:
- Yes
- Leaf Length:
- < 1 inch
- Leaf Width:
- < 1 inch
- Leaf Description:
- 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.
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Stem:
- Stem Is Aromatic:
- No
- Stem Description:
- Prostrate stems branch
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Landscape:
- Landscape Location:
- Pond
- Landscape Theme:
- Water Garden
- Problems:
- Weedy
