The north winds ripped the remaining maple leaves off the trees this weekend. The dry winds and low humidities associated with the cold front, coupled with the flammable one hour fuels sent up a few concerns from our fine friends at Springfield NOAA. Moisture still exists in the woods, and leaf litter is nice and fluffy and fresh. With the first frost event comes the delicate "petals" of frost flowers. These fragile sculptures occur in shady areas, or in the morning hours before the sun has a chance to reach the floor.
Frost flowers are formed when the sap in certain plants freezes, thereby expanding in the stem and causing the formation of small fissures. Water is drawn up through the stem, but as it exits the cracks, it freezes upon contact with the air. As capillary action pulls more water through the stem, the ice is forced out of the cracks, curling into delicate formations.
In the Ozarks, frost flowers occur in a handful of species. Among them are ironweed and snakeroot, both very common fall blooming wildflowers. Every frost flower is different, some more ornate than others. They're extremely delicate, breaking at the slightest touch. I've seen prettier ones than I saw today, but as harbingers of winter, they always remind me of the crisp morning air broken by the loud cackling of pileated woodpeckers.