Any of various tall grasses that flourish with abundant water (noun)
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Use "tallgrass" in a sentence
"The prairie, especially the dominant "tallgrass" prairie, is among the world's most fecund environments."
"Across the Kansas Flint Hills, farmers and ranchers are up in arms over plans by wind developers to erect hundreds of spinning turbines astride hills and ridges that encompass the largest expanse of tallgrass prairie left in North America."
"Finally, a very special thanks goes out to Michele Hill for tramping through the Kansas tallgrass prairie with me."