Jim McKenney asks, "Do irids have petioles?" Sometimes the flower is sessile, but I was referring to the very short (in the case of N.northiana) stem supporting the flower. In N.gracilis, this stem is long. I don't know what to call it besides petiole. It's different from the stouter stem (which I'm calling the peduncle) connecting the whole flowering business to the scape. The scape is winged and looks like a leaf, especially as the spathe is green and in line with the scape, while what I am calling the peduncle escapes from this pair, and is not winged. But, my naming could be wrong.