Here's a page from my current novel notebook -- perhaps another reason why I'm plagued with mushrooms in the yard this summer:
These are Flammulina mitus, commonly known as winter mushrooms, which according to my reference source are " . . . always found growing in clusters on dead, rotting elm and aspen trees." I'm using their startling and rather alien appearance to help me visualize some non-human architecture.
Image credit and ref source: Thoreau Revisited ~ Diary of a Country Year by Stephen J. Krasemann (1973, ISBN# 0-87294-045-4)