Money plant's flowers are striking in the spring garden, but the name alludes to the round, flat seedpods that resemble coins. It's botanical name, Lunaria (as in "lunar") comes from their resemblance to the moon.
Money plant is a biennial, meaning it grows leaves the first year and flowers the second. After flowering, it dies. However, it readily reseeds itself to create a permanent stand. (If you don't want lots of seedlings, just cut off the seedpods.) It prefers part shade and moist soil.