One of the special properties of water is that it expands when it freezes. Like a bursting water pipe, the tender skin of the plant stem splits under the pressure of the expanding ice. Because of the cell structure of the plant's stem, fissures occur in tiny vertical rows. Capillary action in the plant's veins pumps the moisture out through these minuscule cracks like translucent ribbon candy. As crack after crack yields a layer of ice, the total effect resembles the many layers of a flower petal.
Air bubbles trapped in the ice makes it appear frothy white.
If the air is cold and still when a frost flower forms, the ice layers push straight out into large silvery feathers. When conditions cause the leading edge of ice to thaw slightly as it forms, the frost flower will curl inward around the stem like cotton candy on a stick. Each layer of ice is so thin that the total frost flower is almost weightless and will shatter like glass if touched. Frost flowers occur in many parts of the world and all across the state of Missouri. However, only a few species of plants produce frost flowers, and the formations never occur in exactly the same manner from one year to the next, or even from one night to the next.