I have posted in the "name this plant" area and everyone keeps on sending links to different lilies. Last year I had 2 unusual plants appear in one of my flower beds. These had leaves that reminded me of an iris, but the leaves of both plants were fanned out almost perfectly. The plants both flowered in August (I'm in Wisconsin; zone 5.) The flower came up as a single stem, but it had a couple branches and a lot of little flowers on the branches. I think they were orange if I remember correctly. Each little flower eventually became a seed. The seeds looked like morning glory or iris sized seed and they were black. I am just starting to mess around with starting plants from seed. Last year I was "winter sowing" seed pods that I found here and there. That is most likely where these 2 plants came from. I am now trying to start store bought seeds to increase the number of flowers in my gardens this year. In an experiment a few months ago I started a flat with the seeds from last year. I soaked the seeds for several days and used a heat mat to get them going. I now have about 100 plants from these seeds! The flowers on these plants were really small. Maybe 1/4" across or so. The "branches" of the flower stem reminded me of an orchid. These plants were found in an area I would consider part shade.
Here is a link that might be useful: photos