Bois d'arc flowers are not showy. Both male and female flowers are inconspicuous. This year, the bois d'arc flowers in the arboretum did not go unnoticed, but unfortunately the photographic lens caught them a little late. Below are a couple of pictures from the lone bois d'arc in the arboretum.
We appear to have a male bois d'arc. Oregon State University has a nice picture illustrating the difference between male and female flowers. You can find it here.