What is the name of the broad expanse of flat land in the western United States and western Canada  where the species of plant called the Polygonum sawatchense of the buckwheat family be found?
Great Plains The Great Plains (sometimes simply "the Plains") is the broad expanse of flat land (a plain), much of it covered in prairie, steppe and grassland, that lies west of the Mississippi River tallgrass prairie states and east of the Rocky Mountains in the United States and Canada. It embraces
Ecology of the Rocky Mountains The ecology of the Rocky Mountains is diverse due to the effects of a variety of environmental factors. The Rocky Mountains are the major mountain range in western North America, running from the far north of British Columbia in Canada to New Mexico in the southwestern United States, climbing from the Great Plains at or below 1800 ft to peaks of over 14000 ft . Temperature and rainfall varies greatly also and thus the Rockies are home to a mixture of habitats including the alpine, subalpine and boreal habitats of the Northern Rocky Mountains in British Columbia and Alberta, the coniferous forests of Montana and Idaho, the wetlands and prairie where the Rockies meet the plains, a different mix of conifers on the Yellowstone Plateau in Wyoming and in the high Rockies of Colorado and New Mexico, and finally the alpine tundra of the highest elevations.