Shrooms in a pot

This morning, coming up to my office, I saw these little guys poking

their heads up in a plant-pot on a landing in the stairwell. It's not

often I see mushrooms in the plants around my office but they are

welcome guests. I went back a few minutes ago to get some pictures.

Both are about three cm tall, by the way and there is a withered patch

of the brown kind in the background.



I have little hope of figuring out what the spindly little brown

mushroom is. The yellow one seems pretty identifiable, even though my

powers of identification are low this morning. At first, I thought it

was a young Amanita muscaria, since they are far more commonly yellow

here than red. But, on second thought, it doesn't look like that (the

scabby bits are coloured rather than uncoloured). Then, based on that

flakiness, I thought it could be one of the common Agaricus spp (they

are popping up on lawns just outside my office this week). But they

don't tend to be yellow, and they don't tend to have stipes like this

one.



What suggest you?