Lepiota cepaestipes or Leucocoprinus cepaestipes
Look here! A delicate white mushroom growing in my mulch pile! It just goes to show you, if you never get around to spreading your mulch, it will eventually become a garden of its own!
This diminutive species is common in urban areas because it likes to grow in wood chips. The household name for it is Onion-stalk lepiota, because the stem resembles a young onion stalk.
One thing’s for sure, Lepiota cepaestipes grows quickly. Over the course of one day it morphs from the tiny “egg” stage, to a beautiful bell-shape. Within a few more hours it flattens out to a lovely parasol shape. The fully-opened cap may have a raised area in the center, called an umbo.
The caps are white or cream-colored, and usually have a dark-colored, gray/brown central disk. Look closely and you’ll notice the surface of the younger caps have a granular texture; they will later develop tan scales. The edge of the cap is lined with fine striations.
Turn the cap over and the gills underneath are white and free from the stem; the color fades quickly to off-white or beige. The spore print is white.
The stipe, or stalk, is initially white, fading to pink with age. It usually shows a ring leftover from a partial veil.
At full size, Lepiota cepaestipes measures about 2 inches in height; the caps will be 1 to 2 inches wide.
Look for Onion-stalk lepiota late in the summer or in the fall. As I noted earlier, it often grows on mulch in urban ares or on woody litter in the forest.
The photos below were taken in mid-September in Blacksburg.