A Ruana is defined as a woolen covering resembling a poncho. I weave these on my largest loom, using heavier weight 100% wool yarn.
They are woven in 2 pieces - two long rectangles. A seam is stitched down the centre back, joining these two pieces from the back of the neck to the back hem. It sits comfortably over the shoulders. There is an opening down the centre front, to the hem that drapes and hangs into what looks like a long triangular collar.
My ruanas are basically a thick, soft & sleeveless rectangular blanket.