Can anyone help me identify some very cute flowers that pop up each spring in my garden? They are small, early-blooming spring bulbs. The white flowers face downward, about 2 cm (3/4 inch) long, and have 3 petals. In the center is a smaller cup-shape structure (sort of like a daffodil) which is also white, but has lime green in the middle, surrounding yellow reproductive parts. The whole flower is only about 3-4 inches tall, and comes up at the same time as crocus. I am in zone 5 Ontario.