The yellow flowers in the middle are Lemon Lilies. They have a wonderful citrus odor, and fairly strong at that. They are just as hearty a plant as a Day Lily, but they have a thinner and smoother stem, and the flower is a little more delicate. Also, the leaves are greener and more grass like.
To the right is a Sedum. To the left is Geranium, the common variety. Behind are Siberian Irises. In front is a tiny Iris I found in an herb garden in Maine. Crested Iris.