Whilst all these iris prefer moister soils, ideally in full sun, some will grow in the water as marginals. I. pseudacorus and I. x robusta 'Gerald Darby' are all suitable.
Iris forms are legion, and almost all attract pollinators, especially the larger bees. The only possible exceptions are those highly bred, flouncy cultivars whose petal modifications may make nectar in particular more inaccessible. Some, like the winter/early spring-flowering forms such as the reticulata and unguicularis types and the species that produce bright berries (especially I. foetidissima) provide an important food resource for winter birds, from pheasants to blackbirds.