Often in the fall, after a hot dry summer, I see clumps of a bright orangey-yellow gelatinous substance on trees or logs in the forests where I hike. I knew it was a fungus but today decided to find out more. It is, in fact, called 'jelly fungus' though I like its other names better: witches butter, or - my favourite - yellow brain fungus. You can see why:
|Yellow brain fungus|
Apparently the fungus was there all summer, but in hot dry weather it is small, nondescript, and virtually unnoticeable. When the rains come, it acts like a sponge, absorbing up to sixty times its weight in water!