Auther, I am hardly an authority. I have grown Pennyrile. I could only find "Iron and Clay" variety in my google search. They are probably not the same variety, as Sandhill Preservation Center sells them both, as separate varieties. The Iron and Clay is described as a very old variety the slaves brought with them from Affrica. It is described as a good cover crop with sprawling vines. SHP describes Pennyrile as shorter, which was not my experience. Also, from pictures, I don't think the seeds are the same color.