Glyceria fluitans
water manna grass
Europe, North Africa, and temperate western Asia
Overview
Glyceria fluitans is a perennial aquatic grass forming loose stands 12-36 inches (30-90 cm) tall, with stems that float on the water surface before turning upward. Stems are soft, spongy, and root at the lower nodes, spreading into patches 24-48 inches (60-120 cm) across. Leaves are flat or folded, 4-10 inches (10-25 cm) long and 0.2-0.4 inch (5-10 mm) wide, bright green to yellow-green, with a blunt, hooded tip. Leaf sheaths are smooth and somewhat inflated. Flowering panicles are narrow and one-sided, 6-16 inches (15-40 cm) long, with slender spikelets 0.4-1.2 inches (10-30 mm) long pressed close to the branches; they are green and ripen to straw-brown. The grass grows in shallow standing or slow-moving water and on saturated mud, tolerating seasonal flooding to about 12 inches (30 cm) deep. Growth slows on drier ground, where stands thin and leaves yellow. In flowing channels the rooting stems can spread across the surface and reduce open water. The seeds were historically gathered as manna grits for food in parts of Europe.
Native Range
Native to Europe, North Africa, and temperate western Asia. Grows in shallow fresh water, ditches, pond and stream margins, marshes, and seasonally flooded mud, from lowlands to about 3,300 feet (1,000 m). Naturalized in parts of North America.Suggested Uses
Planted at pond and ditch margins and in wetland restoration for bank stabilization and waterfowl habitat. The rooting stems spread across open water in small ponds, so it is generally kept to larger water bodies or contained margins. Seeds and foliage are eaten by waterfowl and grazing livestock.How to Identify
Appearance
Size & Dimensions
Height1' - 3'
Width/Spread2' - 4'
Colors
Bloom Information
Detailed Descriptions
Flower Description
green ripening to straw-brownFoliage Description
bright green to yellow-greenGrowing Conditions
Sun Requirements
Requires 4-10 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Care & Maintenance
Care Guide
Grows in full sun to partial shade in shallow fresh water or permanently wet soil at the edges of ponds and ditches. Establishes from seed or from rooted stem fragments pressed into wet mud in spring. Water depth from 0 to 12 inches (0 to 30 cm) suits it, and stands thin where the soil dries out in summer. The rooting, floating stems spread to cover small ponds within 2-3 seasons. Cutting or raking stems in summer limits the spread. No serious pests or diseases affect it under typical conditions.Pruning
Cut or rake out excess stems in summer to keep open water in ponds and channels; regrowth follows from the remaining rooted nodes. Removed material is drained at the margin before composting. Stems left uncut spread across the surface and reduce open water.Pruning Schedule
J
F
M
A
M
J
J
A
S
O
N
D
summer
Container Growing
✓ Suitable for container growing