Several years ago a house on our street was foreclosed upon. Before the bank took the keys, the owner gave me permission to go through his garden and pilfer some of the perennials. I took three of these:
What is it?
For most of the year it's just a clump of green grass. Then late in the summer a single flowering stalk shoots up. It's so cheering to see that purple blossom just as the rest of the garden starts to fade into beige-ness.