purple gooseberry. unknown if it's an old prairie cultivar, or a seedling from one. I know the bush was there 25 years ago at our old farm, it's crazy vigorous in full shade, and it has oval shaped fruit that ripen to a deep purple. I picked some today as they've just transitioning from green to purple, and also some pixwell for comparison (last photo). The pixwell are smaller and more round, so that seems to rule it out. doing some research, there are old cultivars that have mostly disappeared, I wonder if this is one of them. downing, houghton, smith, red jacket, industry, chautauqua .. all originating from around 1890-1960