B&W images of flowers have always struck me as missing something - like color. Making a good looking B&W image of an object that is beautiful largely because of its color is difficult - IMO. I guess that's a reason for working at conversions of flowers from color to B&W - to learn how to make the best of the situation. Here's what I came up with today - it's one of four and the other three start at http://www.pbase.com/ed_k/image/99581915 (plus two "next" clicks).
Strove for full tonal range, good contrast and detail and - the photo judge's cliche of "white whites and black blacks". Every one of Ansel's 10 zones are present and accounted for.