Don't know what type of fungi it is, but I would remove them, they aren't going to do any good and that way your onions don't have to share.
I was watering my onion seedlings and I found these tiny mushrooms growing in one of the folded newspaper pots. The odd thing is that I used a bagged soil mix, so I was surprised any spores found their way in, unless they were borne on the newspaper. Can anyone ID the fungus? Should I remove it or can I leave it for my own amusement?
