Finding Haareis

Day 100: Hair ice has been on my mind for the last several days, given recent weather conditions, but I have to admit I wasn't thinking about it when I set out for a short walk in a local county park. I was near the top of the one-mile loop when I spotted the first piece alongside the trail, and my jubilant cry of "Haareis!" must have been rather bewildering to the couple walking their dog the opposite direction. They weren't curious enough to ask as they passed me by, but by then, I had already taken pictures and I doubt that they even looked down to see what had grabbed my attention. A little further on, I spotted another example of this fascinating phenomenon. You see, true haareis (hair ice) forms only in the presence of a specific fungus, Exidiopsis effusa. It occurs on decaying deciduous wood and only under certain conditions. Although the precise mechanism of the fungus' role is not understood, it has been suggested that it may provide a natural antifreeze which stabilizes the formation of ice crystals. It has been noted that the ice "hairs" form at the openings of medullary rays (a cellular structure formed in active cambium, perpendicular to the growth rings of the plant). The "hairs" are also similar in diameter to the medullary rays (roughly 0.02 mm). It should not be confused with ground frost (a type of hoar frost which forms in soil).

Hair Ice

Day 102: Hair ice (aka haareis or frost-beard) occurs only under certain conditions, all of which I felt sure were present this morning, and I was not disappointed. This unusual and beautiful ice formation is most likely to be found in northern broadleaf forests. Although temperature and humidity play major roles in its development, the most crucial element is a fungus called Exidiopsis effusa which provides the "scaffold" on which the ice crystals form. The fungus' role is not completely understood, but it has been suggested that it may provide a natural antifreeze which stabilizes the formation of ice crystals. The ice "hairs" form at the openings of medullary rays (a cellular structure formed in active cambium, perpendicular to the growth rings of the plant) and may attain lengths up to eight inches.

Hair Ice

Day 141: Over the course of these posts, I have shown my readers rare plants and fungi, but how about a rare ice? Hair ice occurs only in a narrow window of coinciding events which include temperature, humidity, latitude, type of wood (deciduous) and degree of its decay, and...are you ready for the punch line?...a fungus called Exidiopsis effusa. That's right. Without the fungus, hair ice does not form. The precise mechanism of the fungus' role is not understood, but it has been suggested that it may provide a natural antifreeze which stabilizes the formation of ice crystals. It has been noted that the ice "hairs" form at the openings of medullary rays (a cellular structure formed in active cambium, perpendicular to the growth rings of the plant). The "hairs" are also similar in diameter to the medullary rays (roughly 0.02 mm).

I encountered hair ice for the first time this year about a month ago, and found myself in something of a pickle when my camera battery went dead. Oh, I was ready for that. I had the spare in my kit. However, I was soon to discover that I had apparently forgotten to put it on the charger as I usually do. Hair ice all around me, I had not one but two dead batteries! Since that day, I have been waiting for the right conditions to occur again, and with my second cup of coffee still settling under my belt, I geared up and headed out for Big Bridge, fairly sure I was going on a wild goose chase. Indeed, when I got to the site where I had seen the hair ice previously, my prospects looked pretty bleak. Still, I made a foray into the brush to hunt for it and found one small cluster just as I was about to give up the search. That inspired me to push deeper through the tangled salmonberry vines where I was rewarded with this classic curled specimen. As I knelt to photograph it, the first rays of sun touched the leaves beside it. Had I been half an hour later, it would have been gone.