Virgin's-bower has male and female flowers on separate plants. This is the pistillate flower. The initial image is staminate.
I have always pronounced Clematis with the emphasis on the second syllable. A couple of years ago I heard Sam pronounce it with the emphasis on the first. As everybody knows, I like to think I know what I'm talking about. Then it turns out I can't even talk about it right! Sam's way is preferred. It's always good to be humbled, even in such a small way. One small bite of a very big job. Thanks, Sam.