Hi,
the plant is not in my garden it is a photo from a shop, where it is sold as T. luteum. Not once I got yellow trillium from others that in fact were not that species. Now I decided to buy it in one of Polish nurseries, but when I saw their photo of the plant I knew that it was wrongly identified. I am not sure what species it is, and I wanted to inform the shop to do the correction, but I hoped I could give them a proper name of it.