Whistling Jack

I love the name and I love the flower, although I've never heard it whistle. It's also known as Sword Lily or Eastern Gladiolus (Gladiolus Communis Byzantinus). We have quite a few spreading through the garden. It now grows wild in the South West of England having been cultivated in the Scilly Isles as a cut flower and then escaping into the wild. I've just read that it's called Whistling Jack, because you can put the long leaves between your thumbs and blow to make them whistle, as I used to do with grass. When it stops raining again, I'll go outside and try.