The gauzy layers of ice appear to sculpted by pixies. Due to their fragile nature, frost flowers rarely last past sun-up.
Source: en.wikipedia.org
The formation of frost flowers can only happen when freezing weather conditions occur while the ground itself is not frozen. The sap from plants will expand, causing long, thin cracks to form along the length of the stem. Water is then drawn through these cracks and freezes upon contact with the air. As more water is drawn through the cracks it pushes the thin ice layers further from the stem, causing a thin "petal" to form.
Source: columbiamagazine.com
Source: usdagov