A first try at focus stacking, following Rajan Parrikar's suggestion. Used was the Canon 5d2 with the 100mm macro, the individual shots were obtained by varying the autofocus point among the 9 choices that Canon provides. Each individual shot was at ISO 400, f/11, 1/30 seconds (which is what the available lighting dictated). The slight breeze was a confounding factor.
This simple tutorial on youtube is what I followed.
However, I still have a lot to learn, because while the full sized stacked image was fine, when I tried to crop it or resize it, it developed annoying artifacts - little white lines running horizontally or vertically. I finally saved it as a full size jpeg, and then trimmed off the edges of the frame as a jpeg, resized, and here it is. In this size, the effect of focus stacking may not be clear, but in each of the individual shots only part of the beard of the iris was in focus, in the composite image, all of it is in focus.