Reed Manna Grass – Oneida County Aquatic Invasive Species Program

Reed Manna Grass   Glyceria maxima

Identification: Reed manna grass is a perennial, rhizomatous grass with unbranched stems. Leaf blades are flat and 30-60 cm long. They are shallowly grooved with prominent midribs. Leaf margins have short, stiff hairs that are rough to the touch. Reed manna grass is up to 2.5 m tall. The variegated form of the plant has distinct cream and green stripes on the leaves.

Ecology and Natural History: Reed manna grass is native to temperate Eurasia. It is typically found in marshes, meadows, and along shorelines. It usually reproduces by rhizome. It is thought to be introduced intentionally as a forage species or an ornamental plant.

Impacts of Introduction: Reed manna grass can form large monotypic stands, reducing diversity. Since growth begins in early spring, it can easily out-compete other species by beating them to valuable resources. Reed manna grass is an ecosystem engineer that can change an entire wetland by converting fast-flowing, oxygen-filled streams into partially anaerobic swamps.

It is PROHIBITED to possess, transport, transfer, or introduce reed manna grass without a permit in the state of Wisconsin.
Glyceria maxima variegata 
​Variegated Reed Manna Grass
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