Image Credits to chemistryworld.com

 The Skeleton Flower, a white woodland blossom whose petals turn crystal clear when they make contact with water . 

Diphylleia grayi, the scientific name of the transparent flower, can be found in only three parts of the world. The plant grows on moist, wooded mountainsides in colder regions of Japan, China and the Appalachian Mountains in the United States, and is instantly recognizable by the rare flowers’ large, umbrella-like leaves. The fading of the color in the petals when wet happens because of a loose cell structure present in the white flowers and not due to the pigment being washed out. When it rains, water fills in the cells of the petals, thus turning it clear, same as water. It is unclear, though, whether this trait gives advantage or disadvantage to these small flowers.

When the leaves dry out, they turn back to being white.