I purchased some calla lily bulbs from OS and when they arrived they were quite small, around the size of an average garden pebble.

half of them have come up and all 8 of them look the same but not like a calla lily. The leaves are coming up like a bush and in clusters of 6 on each stem, The flower is kind of taking the shape of a lily but the stamen is long, thin and stem like. See photo.

Is this just a juvenile calla lily that needs to mature, and if so, how long will I need to wait, can any one tell me what I have here?

Thanks