Can anyone tell me whether these seedlings are cucumber or zucchini? They are volunteer plants that came up in a garden that has had cucumbers for many years, and zucchini only once, as far as we know, which was last year. There have never been volunteer cucumber plants in this garden, which led us to believe they might be zucchini. I've looked at online images and descriptions of both, and it's too close to call for me. Thanks for any input!