I'm not really familiar with this, but it looks like it should be Helleborus viridis (viridis means green), but those bloom in the late winter or spring, so maybe it's not that. I see now that Margot is thinking the same genus. (The screen showed me that another posting came in while I was doing this one. I haven't seen that before. I like it.)
Thanks a lot. I got something similar in McLennan Park in Richmond. Someone told me that is Winter Rose or X'mas Rose (Helleborus species. I post 4 fotos for comparison.
Hellebores are prolific self-seeders. Lenten roses - Helleborus x hybridus (formerly Helleborus orientalis hybridus) are hybrids of at least nine species. Very confusing. I've noticed in my garden that the white-flowered hellebores often 'fade' to greenish colours which is not much help in identifying them except probably as Helleborus x hybridus.
Several Helleborus can have green flowers. Helleborus hybridus. Helleborus multifidus, Helleborus argutifolius, Helleborus viridis, etc etc Need to see whole plant with leaves. Pics below...if you enlarge pic name will show.
