These are hardy, damp-loving irises, widespread in the Northern Hemisphere. They make spreading mats of rhizomes, and flower best if planted in sunny places, so long as the dampness, or even wetness, is ensured. They include our British native flag iris.

Iris pseudacorus is the wild flag iris, common in wet places, particularly in the west of Scotland, and growing wild immediately adjacent to our garden. The flowers are bright yellow and large, and if the plants are in good soil they produce many more flowers than you usually see on the ancient and extensive patches in the wild.