False parasol mushroom

Spotted growing at the edge of a strip of lawn between the sidewalk and street at the edge of a driveway in a suburban development. The first image shows the mushroom at the time of the last observation on Sep 7. It was one of two individuals first spotted on Sep 5 at which time it had just emerged but was already ~ 80 cm tall and its stem was its final size (~ 10 mm in diameter). Its cap, ~ 20 mm in diameter, was still closed and mostly covered with a brown universal veil (image 2). By the night of Sep 5, though its cap remained closed, it had grown to 100 mm tall. By Sep 6, it was ~ 130 mm tall--its final height--and its cap had opened into a convex shape ~ 110 mm in diameter. The universal veil had disintegrated into brown scales (images 3 and 4). The gills were white and it had a dark brown annulus; the stem was white above the annulus (image 5--the mesh visible at the left edge was in the mirror used to get the image, not in the spotting). By Sep 7, the cap had lost its convex shape and
the gills had darkened, appearing grayish (image 6). When the spotting site was checked in the late afternoon of Sep 7, both individuals were gone, without trace, preventing further monitoring. To close the loop, the second individual, which emerged nearby and was not monitored, was deformed. Its opened cap was segmented, like blades on a fan and twisted.