Mushroom on a Sandy Beach

Don Said: the sand under a piece of driftwood. I haven't gotten a spore print but I think the spores are very dark colored. brown/black? the gill attachment is adnexed. The stipes are hollow and contorted. In the picture above (on the note paper) the three mushroom(s) on the left are all coming from one stipe, and it looked like other mushrooms were sprouting from previously broken stipes.
I don't know what these are, and any nudge in the right direction would be appreciated

Sava said: Can you save a few of these for the Herbarium? It'd be interesting to find out what they are.

I recalled something on Mushroom Observer, that may just be your mushrooms: Psathyrella ammophila (http://mushroomobserver.org/observer/observation_search?pattern=Psathyrella+ammophila).