Looks like cucumber. A male flower might be in the vicinity in another garden. If not I wonder if the cucumbers will be seedless? Never heard of a seedless cucumber.

Unless you are trying to create special hybrids bugs pollinate long before you get to try.

I do have a pickling cucumber plant also that has only male flowers on it so far (it's still young) but it just didn't make sense to me that the first plant wouldn't produce any male flowers. I never heard of this happening and couldn't find anything on the web either. This plant with female flowers only is younger than the cucumber plant with just male flowers.