They goby several names. Surprise Lilly, Naked Lady (because no foilage), and Resurection Lilly.

They should make an attractive green clump of tall green, very grass-like leaves in the spring for a few weeks. They will die off and you can mow them at that point. A few months later these stems and flowers 'resurrect' from the bulb.

You can divide the bulbs and spread them about every two or three years. I believe the bulbs should be 6-7 inches deep to get good flowers. Check that last part for sure.