Tall Manna Grass, Reed Sweetgrass, Giant Manna Grass

Growth Form:  Grass

General:   Perennial, rhizomatous grass grows from 1.6 - 8.2 feet tall.

Flowers:   Flowering portion of plant open with many branches (panicle), branches with short, stiff hairs, strongly drooping at maturity with 50 + flattened (laterally compressed) spikelets, spikelets 0.24 (0.39) inches long, egg-shaped with 4 - 10 minute flowers.

Fruits and Seeds:  

Leaves:   Flat, 7 or more on stem, 8.6 - 11.4 inches long and 0.3 - 0.8 inches wide, shallowly grooved with prominent midribs. Leaf sheath closed for most of length and rough to touch . Leaf edges with short, stiff hairs.

Stems or Branches:   Unbranched, 0.3 - 0.5 inches thick.

Threatens:   Threatens freshwater communities, especially shallow water wetlands.

Look-Alikes:   Fowl Manna Grass, G. striata, very common, shorter (1.64 - 4.0 feet tall ). Floating Manna Grass, G. septentrionalis (common) and G. borealis (very rare), spiklets linear, 0.39 inches or longer. Pale manna grass, G. pallida, leaf sheaths open, split to base. Rattlesnake Grass, G. canadensis, and Reed Manna Grass (G. grandis), leaves on stem 3 - 6, leaf sheaths smooth.

Distribution:   Native to temperate Europe and Asia, from the British Isles to Japan and Kamchatka. Found in Massachusetts, Alaska, SE Wisconsin (Racine County), and Lake County, Illinois.

Other Links:  

http://tncweeds.ucdavis.edu/esadocs/glycmaxi.html
http://nas.er.usgs.gov/queries/FactSheet.asp?speciesID=1120
http://www.issg.org/database/species/ecology.asp?fr=1&si=891&sts=