First of all, thanks Ed, for your insight and suggestions.
I think the shot was perhaps a little deceptive, as it was taken from underneath the flower, not side-on (the stamen and pistil are not visible from above, they open downwards).
However I see your point about the tree trunk being distracting (I thought it would give interest...ooops!).
I did actually take another shot of this flower against the sky on the same day though, and I would like to submit it to see what you think!
Always nice to get some feedback on Ed's comments - thanks Tanya.
Please do submit one of your other photos. It would be good to see how it differs from your original submission.