We could not find any pictures of the "rosette" of Chasmanthium latifolium (Inland sea oats). The first picture below is how they should look probably in April. The next picture is the tattered and gray condition mentioned in your quotation from our webpage on the plant condition in February. At that point, we would recommend going in and trimming back to about 6 inches above the soil. They will be brown spindly sticks but it will remind you where the plant is. They may already have some little grassy spikes sticking up at the point, coming up from the root, and will continue to grow until they look like the third picture below.