Very equally round like a sphere, tried to get lots of photos let me know if something more specific is needed.
The undulations are hollow and will break fairly easily. Growing on what I believe is a dead hardwood. No obvious parasitism going on. No discernable odor. First micrograph at 400x (1div=2μm) showing septate 4-spored basidia. Second micrograph at 1000x (1div=1μm) showing clamp connections?
Growing on well decomposing hardwood
Growing on dead hardwood stick.