Zizania palustris L.  
Family: Poaceae
northern wild rice
Zizania palustris image
Robert W. Freckmann  
Etymology: Zizania: from adaptation of zizanion for an ancient name of some wild grains
Plants: erect/floating annual, < 7' tall, aquatic, emergent grass
Leaves: first leaves float; later emerge, wide, flat
Flowers: 5-parted, each female spikelet has 1 flower with 3-ribbed, shiny firm lemma; inflorescence spikelets, female at top
Habitat: wet; in water to 40" deep, rivers, lakes; in silty, mucky soil
Conservation Status: Native
Zizania palustris image
Eric J. Epstein  
Zizania palustris image
Kitty Kohout  
Zizania palustris image
from USDA Plants website  
Zizania palustris image