During the winter, prairie becomes nearly monochromatic. The scarcity of color exposes the architecture of the plants. It’s as if the prairie has been deconstructed before our eyes, stripped down to its framework before being rebuilt for the next season.
Switchgrass (Panicum virgatum) in winter prairie. Sarpy County, Nebraska
The Prairie Ecologist 
There is a good reason this genus is called Panicum. The ‘panicle’ of Switch Grass breaks off and causes it to travel across the prairie like tumble weed.
I’ve found the more time I spend in the woods and prairies in the winter the easier it is for me to identify plants at any other time of the year. All based on having a greater knowledge of their structure and appearance. Spending time outdoors in all seasons is something that has really helped me with my plant ID. Also, winter time solitude is nice as well.