We've had quite a few nights with temps below freezing down in the Florida panhandle this winter. While out checking some of our wetlands in the morning, I was surprised to see dozens of these delicate and beautiful ice structures formed out of plant fluids being drawn up through nearly dead annual herbs (seemingly all one species of asteraceae but not sure on id in this shape). The vascular tissue had apparently ruptured from the expansion of the freezing fluid, yet the fluid continued to flow, freezing as it left the plant tissues to form numerous fine sheets of ice. That is what seemed to make sense to me, but I would love to hear your thoughts if you have any. I would also be interested to hear if anyone has seen or heard of this before. The structures were very fragile and would shatter easily and pieces would melt in the hand rather quickly. I was impressed, and thought that it would be difficult for any human to form anything quite so delicate out of ice.
Follow up: My friend Ben told me the term for these icy structures is "Frost flowers." Here's a
link to a more in depth description of how they form. Thanks Ben!