Tall Manna Grass

(Glyceria maxima)

Semi-aquatic, perennial grass with unbranched stems that get up to 8’ tall. Reddish tint on the lower parts of the stems.


Other names for this plant include:

  • Common names: reed sweetgrass, reed manna grass, English water grass
  • Scientific names: G. aquatica; G. spectabilis; Molinia maxima; Panicularia aquatica

Ecological threat:

  • Tall manna grass invades wetlands, including swamps, lakes, ponds, slow-moving rivers, creeks, ditches and wet pastures, where it forms monospecific stands that are capable of crowding out native vegetation.
  • It degrades wetland habitats because it is not suitable for nesting and is a poor food source for wildlife.
  • Tall manna grass has been sold as an ornamental in a variegated variety.
  • Young shoots can cause cyanide poisoning in cattle if used as forage.
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