It's Iris psuedacorus, otherewise known as the yellow flag They tend to grow best on the edge of ponds, bog gardens etc. I have several scattered around the garden (my pond just aint that big so I divide them occasionally) and they seem to grow in almost any position.
When I've worked out how to add a picture to this message I will do so. In the meantime I'll e-mail you with an attachment.
P.S. Kathy, check the Photos forum for my picture
This message was edited Wednesday, Jun 6th 5:41 AM