Looks like Iris crisata alba.

Thank you Owdboggy. I was unsure whether this was I. cristata alba or I. gracilipse alba. They seem to be very similar.

They do indeed.
Looking again I would incline more towards I gracilipes alba, if only because of the width of the falls.

If you are having label problems, then try black labels with a silver pen. I trialled this last year leaving a label e posed over the winter and the writing never moved.

Thank you Owdboggy. it is a lovely little plant. I will give that a try Barbarak. When I sow seeds I print and laminate labels for the pot. They last well. Handwritten labels on wood or plastic have never lasted over the winter.

I find that pencil on white plastic works well, and I have legible labels which have been outdoors in all weathers for over 7 years. When I've tried so-called indelible ink in the past, it's barely lasted a year!

I use black ones to marks areas that have bulbs in the summer ( I sometimes slice bulbs when planting out summer bedding so need labels) and the deciduous plants in the winter. They don't look conspicuous like the white ones.

Thank you Rosierose. I dk why pencil on white plastic does not last in my garden. The black labels will certainly be less conspicuous Barbarak.