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The formation of frost flowers is dependent on a
freezing weather condition occurring when the ground is not already frozen. The
sap in the stem of the plants will expand (water expands when frozen), causing long, thin cracks to form along the length of the stem. Water is then drawn through these cracks via
capillary action 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.
The petals of frost flowers are very delicate and will break when touched. They usually melt or
sublime when exposed to sunlight and are usually visible in the early morning or in shaded areas.
Examples of plants that often form frost flowers are white crownbeard (
Verbesina virginica), commonly called frostweed, yellow ironweed (
Verbesina alternifolia),
[2] dittany (
Cunila origanoides),
[3] and
Helianthemum canadense.