We've barely had winter, but, almost right on cue, the fabled January Thaw has taken hold of the weather and the temperature is nudging 60. I took advantage of the warmth and headed up a favorite trail in search of an area that, last year, proved especially amenable to unusual wildflowers. There were no signs of any plants trying to take advantage of the ridiculous conditions, and I thought that the only activity I'd encounter were numerous felled trees, the work of local beavers now busy in their ice-free pond. But, I discovered quite by chance, they weren't alone. A brilliant-colored fungus was also active in the warmth. This rubbery, brain-like mushroom is known as "Witches' Butter," and it's a common dazzler that grows throughout the year but seems most abundant—or maybe just most obvious—in cold conditions. This member of the Jelly Fungi is, I'm guessing, properly called Tremella mesenterica, the Yellow Witches' Butter, but to be certain, I'll have to take some samples and do considerable microscopic analysis. Why do I ever leave the house without the proper collecting equipment? Why?