The Diphylleia grayi, widely recognized as the skeleton flower, possesses a unique characteristic. Its delicate white petals undergo a striking transformation when they come into contact with water, such as rain. This phenomenon causes the petals to lose their opaque appearance and become completely transparent, resembling delicate, glass-like structures. This change is temporary, as the petals revert to their original white color once they dry.
The Science of Transparency
The skeleton flower’s petals change visually due to their specific cellular architecture. When dry, they appear opaque white because loosely packed cells contain numerous air pockets. These air-filled spaces within the petal tissue scatter light, similar to how snow appears white. This scattering prevents light from passing directly through, giving the petal its characteristic white color.
When rain or other water sources moisten the petals, the water fills these microscopic air pockets. Water has a refractive index, a measure of how light bends when passing through a substance, that is very similar to the plant cells’ internal fluid, known as cytolymph or cell sap.
Replacing air with water significantly reduces the difference in refractive index between the spaces and cell material. This minimizes light scattering, allowing light to travel almost unimpeded. As a result, the petals become transparent, revealing their intricate vein structure. The process is reversible; as water evaporates, air re-enters, and petals regain their white opacity.
Habitat and Ecological Role
The skeleton flower thrives in specific environmental conditions, found on cool, moist, wooded mountain slopes. Its natural distribution includes northern and central Japan, regions of China, and the Appalachian Mountains in the United States. It prefers shaded, damp habitats, often growing under tree canopies where direct sunlight is limited.
Beyond its remarkable petals, the plant features large, umbrella-like leaves that contribute to its common name, “umbrella leaf flower.” After its flowering period, which typically occurs from late spring to early summer, the Diphylleia grayi produces distinctive dark blue or purple berries.
These berries serve as a food source for birds and pollinators, contributing to the local ecosystem. The flower attracts pollinators such as butterflies and bees, and can emit a sweet scent. Its unique properties also make it a subject of interest in botanical studies, offering insights into plant physiology and adaptation.