Photos of frost flowers of American Dittany, Cunila origanoides

Cunila origanoides, American Dittany, Dittany, Common Dittany, Sweet Horsemint, Stonemint, Mountain Dittany, Feverwort. During the first chills of autumn frosts, American dittany produces frost flowers at its base — twisting, white, fluted ribbons of ice. This phenomena is caused by cell sap rising from the still-live root into the stems. As the rising moisture is supercooled it is pressurized, bursting through tissue in the stem, extruding into crystalized ribbons as it hits freezing air. A reward of natural beauty for the earlier riser on a frosty morning . . . See our Virginia Crownbeard frost flowers, too.

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