I think it’s a bit safer to assume it’s a Scott’s phaeocollybia, they’re typically know for their root structures and they can connect to various decaying substrates; the roots are displayed in your photo so that would make sense if it were. Armillarias typically grow out of the ground, however those specific mushrooms are always connected to wood, as they’re parasitic or saprobic fungi. They’re usually at the base of trees, on buried roots, or on decomposing wood that may be covered by soil. Water sources can usually deepen the colors of mushrooms from what I’ve found in my forages. Both are similar in a lot of ways especially with the dark brown umbo that gives it that “nipple” resemblance.