Northern Prairie Wildlife Research Center
Northeast Wetland Flora
Field Office Guide to Plant Species
Atlantic Manna Grass
Glyceria obtusa (Muhl.) Trin.
- Family: Grass (Gramineae)
- Flowering: July-September
- Field Marks: The characteristics that distinguish this species of Glyceria from the others are
the very dense panicles, the 4- to 7-flowered spikelets 1/6-1/3 inch long, and the leaves rough
on the upper surface.
- Habitat: Wet soil; sometimes in shallow standing water.
- Habit: Perennial herb from thickened rootstocks.
- Stems: Upright but often prostrate at the base, usually unbranched, stiff, smooth, up to 4 feet tall.
- Leaves: Elongated, flat or folded, up to 1/3 inch wide, rough on the upper surface, smooth on the
lower surface; sheaths closed and fused.
- Flowers: Borne in spikelets, with many spikelets crowded into dense ellipsoid to cylindrical panicles
up to 8 inches long; spikelets 4- to 7-flowered, 1/6-1/3 inch long, green or tan.
- Glumes: Broadly lanceolate, the first somewhat shorter than the second, pointed or somewhat
rounded at the tip, whitish-margined, up to 1/8 inch long, smooth, conspicuously nerved.
- Lemmas: Broadly elliptic to obovate, rounded at the tip, up to 1/6 inch long, smooth, conspicuously
- Sepals: 0.
- Petals: 0.
- Stamens: 3.
- Pistils: Ovary superior, smooth.
- Fruits: Grains broadly ellipsoid, smooth.
- Notes: This family is called Poaceae by Gleason and Cronquist. The grains are eaten by
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